diff --git a/REQUIRE b/REQUIRE
index 548c914..ed6ec66 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,8 +1,9 @@
 Lint 0.1.60
-julia 0.3.11
+julia 0.6
 Compat 0.1
 Formatting 0.1.2
 DataArrays
 DataFrames
 DataFramesMeta
 Lazy
+Missings
diff --git a/src/TermWin.jl b/src/TermWin.jl
index 32283b0..e2b546c 100644
--- a/src/TermWin.jl
+++ b/src/TermWin.jl
@@ -22,6 +22,7 @@ end
 using DataArrays
 using DataFrames
 using DataFramesMeta
+using Missings
 
 macro lintpragma( s )
 end
@@ -120,17 +121,21 @@ function initsession()
             throw( "terminal doesn't support colors")
         end
         mousemask( BUTTON1_PRESSED | REPORT_MOUSE_POSITION )
-        acs_map_ptr = cglobal( Libdl.dlsym( libncurses, :acs_map), UInt32 )
-        acs_map_arr = pointer_to_array( acs_map_ptr, 128)
+	if is_apple()
+	    acs_map_ptr = cglobal( Libdl.dlsym( libncurses, :acs_map), UInt32 )
+	else
+            acs_map_ptr = cglobal( Libdl.dlsym( libncurses, :acs_map), UInt64 )
+	end
+        acs_map_arr = unsafe_wrap(Array, acs_map_ptr, 128)
 
         start_color()
         # figure out how many colors are supported
         colorsptr = cglobal( Libdl.dlsym( libncurses, :COLORS), Int16 )
-        colorsarr = pointer_to_array( colorsptr, 1 )
+        colorsarr = unsafe_wrap(Array,  colorsptr, 1 )
         COLORS = colorsarr[1]
 
         colorsptr = cglobal( Libdl.dlsym( libncurses, :COLOR_PAIRS), Int16 )
-        colorsarr = pointer_to_array( colorsptr, 1 )
+        colorsarr = unsafe_wrap(Array,  colorsptr, 1 )
         COLOR_PAIRS = colorsarr[1]
 
         init_pair( 1, COLOR_RED,    COLOR_BLACK )
@@ -342,9 +347,9 @@ end
 function titleof( x::Any )
     typx = typeof( x )
     if typx == Module || typx == Function
-        return utf8( string( x ) )
+        return string( x )
     else
-        return utf8( string( typx ) )
+        return string( typx )
     end
 end
 
@@ -387,7 +392,7 @@ function tshow( x; kwargs... )
             catch err
                 bt = catch_backtrace()
                 msg = wordwrap( string(err) * "\n" * string( bt ), 80 )
-                widget = tshow_( msg; title=utf8("Error") )
+                widget = tshow_( msg; title="Error" )
             end
             if widget != nothing
                 refresh( rootTwScreen )
@@ -459,7 +464,7 @@ function testkeydialog()
     win = winnewcenter( 6, width )
     panel = new_panel( win )
     box( win, 0, 0 )
-    title = utf8( "Test Key/Mouse/Unicode" )
+    title = "Test Key/Mouse/Unicode"
     keyhint = "[Esc to continue]"
 
     mvwprintw( win, 0, (@compat Int( (width-length(title))>>1)), "%s", title )
diff --git a/src/ccall.jl b/src/ccall.jl
index e1dff57..eef50e2 100644
--- a/src/ccall.jl
+++ b/src/ccall.jl
@@ -7,14 +7,14 @@ function initscr()
     global libncurses, libpanel
     if  libncurses == false
         try
-            libncurses = Libdl.dlopen("libncurses")
-        catch
             libncurses = Libdl.dlopen("libncursesw")
+        catch
+            libncurses = Libdl.dlopen("libncurses")
         end
         try
-            libpanel = Libdl.dlopen("libpanel")
-        catch
             libpanel = Libdl.dlopen("libpanelw")
+        catch
+            libpanel = Libdl.dlopen("libpanel")
         end
     end
     ccall( Libdl.dlsym( libncurses, :initscr), Ptr{Void}, () )
@@ -66,14 +66,14 @@ function mvwaddch( w::TwWindow, y::Int, x::Int, c )
     end
 end
 
-function mvwprintw{T<:AbstractString}( win::Ptr{Void}, row::Int, height::Int, fmt::ASCIIString, str::T )
+function mvwprintw{T<:AbstractString}( win::Ptr{Void}, row::Int, height::Int, fmt::String, str::T )
     ccall( Libdl.dlsym( libncurses, :mvwprintw), Void,
         ( Ptr{Void}, Int, Int, Cstring, Cstring ),
         win, row, height, fmt, str )
 end
 
 # note that it could in turn call another TwWindow...
-function mvwprintw{T<:AbstractString}( w::TwWindow, y::Int, x::Int, fmt::ASCIIString, s::T )
+function mvwprintw{T<:AbstractString}( w::TwWindow, y::Int, x::Int, fmt::String, s::T )
     if objtype( w.parent.value ) == :List && typeof( w.parent.value.window ) != TwWindow
         # terminal layer. use its pad
         mvwprintw( w.parent.value.data.pad, y+w.yloc, x+w.xloc, fmt, s )
@@ -322,7 +322,7 @@ function has_mouse()
 end
 
 function mousemask( mask )
-    oldmm = Array( UInt64, 1 )
+    oldmm = Array{UInt64}(1)
     resultmm = ccall( Libdl.dlsym( libncurses, :mousemask), UInt64, (UInt64, Ptr{UInt64}), mask, oldmm )
     ( resultmm, oldmm[1])
 end
@@ -332,7 +332,7 @@ function mouseinterval( n::Int )
 end
 
 #hack!
-const mouseByteString = bytestring( Array( UInt8, 64 ) )
+mouseByteString = Vector{UInt8}(64) #unsafe_string( Array( UInt8, 64 ) )
 function getmouse()
     #=
     type Mouse_Event_t
diff --git a/src/dfutils.jl b/src/dfutils.jl
index 42e53f8..a8153c1 100644
--- a/src/dfutils.jl
+++ b/src/dfutils.jl
@@ -22,14 +22,13 @@ defaultAggr( ::Type{} ) = :uniqvalue
 defaultAggr{T<:Real}( ::Type{T} ) = :sum
 defaultAggr{T}( ::Type{Array{T,1}} ) = :unionall
 
-function liftAggrSpecToFunc( c::Symbol, dfa::UTF8String )
+function liftAggrSpecToFunc( c::Symbol, dfa::String )
     if haskey( DataFrameAggrCache, (c, dfa ) )
         return DataFrameAggrCache[ (c, dfa ) ]
     end
     ret = liftAggrSpecToFunc( c, parse( dfa ) )
     DataFrameAggrCache[ (c, dfa) ] = ret
 end
-liftAggrSpecToFunc( c::Symbol, dfa::ASCIIString ) = liftAggrSpecToFunc( c, utf8( dfa ) )
 
 function liftAggrSpecToFunc( c::Symbol, dfa::Union{ Function, Symbol, Expr } )
     if typeof( dfa ) == Function
@@ -71,7 +70,7 @@ function liftAggrSpecToFunc( c::Symbol, dfa::Union{ Function, Symbol, Expr } )
         convertExpression!( cdfa, c )
 
         membernames = Dict{Union{Symbol,Expr}, Symbol}()
-        cdfa = DataFramesMeta.replace_syms(cdfa, membernames)
+        cdfa = DataFramesMeta.replace_syms!(cdfa, membernames)
         funargs = map(x -> :( getindex( _df_, $(x)) ), collect(keys(membernames)))
         funnameouter = gensym("DFAggr")
         funname = gensym()
@@ -130,12 +129,20 @@ function uniqvalue( x::AbstractDataArray; skipna::Bool=true )
         if length(l) == 1
             return l[1]
         end
-        return NA
+        return missing
     end
     if length(lvls) == 1
         return lvls[1]
     end
-    return NA
+    return missing
+end
+
+function uniqvalue( x::Array )
+    lvls = DataArrays.levels(x)
+    if length(lvls) == 1
+        return lvls[1]
+    end
+    return missing
 end
 
 function uniqvalue{T<:AbstractString}( x::Union{ Array{T}, DataArray{T}, PooledDataArray{T} }; skipna::Bool=true, skipempty::Bool=true )
@@ -156,7 +163,7 @@ function uniqvalue{T<:AbstractString}( x::Union{ Array{T}, DataArray{T}, PooledD
         elseif length( l ) == 1
             return l[1]
         end
-        return NA
+        return missing
     end
     if skipempty
         emptyidx = findfirst( lvls, "" )
@@ -172,16 +179,14 @@ function uniqvalue{T<:AbstractString}( x::Union{ Array{T}, DataArray{T}, PooledD
     elseif length( lvls ) == 1
         return lvls[1]
     end
-    return NA
+    return missing
 end
 
 immutable CalcPivot
     spec::Expr
     by::Array{Symbol,1}
-    CalcPivot( x::UTF8String, by::Array{Symbol,1}=Symbol[] ) = CalcPivot( parse(x), by )
-    CalcPivot( x::ASCIIString, by::Array{Symbol,1}=Symbol[] ) = CalcPivot( parse(utf8(x)), by )
-    CalcPivot( x::UTF8String, by::Symbol ) = CalcPivot( parse(x), Symbol[ by ] )
-    CalcPivot( x::ASCIIString, by::Symbol ) = CalcPivot( parse(utf8(x)), Symbol[ by ] )
+    CalcPivot( x::String, by::Array{Symbol,1}=Symbol[] ) = CalcPivot( parse(x), by )
+    CalcPivot( x::String, by::Symbol ) = CalcPivot( parse(x), Symbol[ by ] )
     function CalcPivot( x::Expr, by::Symbol )
         CalcPivot( x, Symbol[ by ] )
     end
@@ -238,7 +243,7 @@ function liftCalcPivotToFunc( ex::Expr, by::Array{Symbol,1} )
     funname = gensym()
 
     membernames = Dict{Union{Symbol,Expr}, Symbol}()
-    cex = DataFramesMeta.replace_syms(cex, membernames)
+    cex = DataFramesMeta.replace_syms!(cex, membernames)
     # keys are the columns. values are the unique gensyms
 
     if !isempty( by ) # micro split-apply-combine
@@ -253,7 +258,7 @@ function liftCalcPivotToFunc( ex::Expr, by::Array{Symbol,1} )
             push!( aggr_args, Expr( :kw, a, Expr( :call, Expr( :ref, :aggrfuncs, QuoteNode( a ) ), lambdasym ) ) )
         end
 
-        bycolsexpr=Expr( :vcat, map( _->QuoteNode(_), by )... ) # [ :a, :b, :c ... ]
+        bycolsexpr=Expr( :vcat, map( x->QuoteNode(x), by )... ) # [ :a, :b, :c ... ]
         aggrcode = Expr( :->, lambdasym, Expr( :call, DataFrame, aggr_args... ) )
         code = :(
             function $funnameouter( _df_::AbstractDataFrame, c::Symbol; kwargs... ) # we need kwargs here for aggregate specs
@@ -311,9 +316,9 @@ function cut_categories{S<:Real, T<:Real}( ::Type{S}, breaks::Vector{T};
     mixedfraction=false,autoscale=:none,conversion=""
     )
     n = length(breaks)
-    breakstrs = UTF8String[]
-    function formatter(_)
-        prefix * format( _*scale,
+    breakstrs = String[]
+    function formatter(x)
+        prefix * format( x*scale,
             precision=precision,
             commas=commas,
             stripzeros=stripzeros,
@@ -332,12 +337,12 @@ function cut_categories{S<:Real, T<:Real}( ::Type{S}, breaks::Vector{T};
     else
         ncategories = n
     end
-    pool = Array(UTF8String, ncategories )
+    pool = Array(String, ncategories )
     if rank
         rankwidth = length(string(ncategories))
     end
     if !rank
-        rankprefixfunc = _->""
+        rankprefixfunc = x->""
     elseif reverse
         rankprefixfunc = j -> format( n+2-j, width=rankwidth ) * ranksep
     else
@@ -347,7 +352,7 @@ function cut_categories{S<:Real, T<:Real}( ::Type{S}, breaks::Vector{T};
         if S <: Integer && T <: Integer && scale == 1
             # we use 1...5, 6, 7...10, 11+etc.
             if leftequal
-                breakminus1strs = UTF8String[]
+                breakminus1strs = String[]
                 for b in breaks
                     push!( breakminus1strs, formatter( b-1 ) )
                 end
@@ -367,7 +372,7 @@ function cut_categories{S<:Real, T<:Real}( ::Type{S}, breaks::Vector{T};
                     pool[n+1+poolindexshift] = rankprefixfunc(n+1+poolindexshift)*breakstrs[n]*"+"
                 end
             else
-                breakplus1strs = UTF8String[]
+                breakplus1strs = String[]
                 for b in breaks
                     push!( breakminus1strs, formatter( b+1 ) )
                 end
@@ -391,13 +396,13 @@ function cut_categories{S<:Real, T<:Real}( ::Type{S}, breaks::Vector{T};
             if leftequal
                 brackL = "["
                 brackR = ")"
-                compareL = utf8( "<" )
+                compareL =  "<"
                 compareR = "≥"
             else
                 brackL = "("
                 brackR = "]"
                 compareL = "≤"
-                compareR = utf8(">")
+                compareR = ">"
             end
             poolindexshift = -1
             if boundedness in [ :unbounded, :boundedabove ]
@@ -425,9 +430,9 @@ function cut_categories{S<:Real, T<:Real}( ::Type{S}, breaks::Vector{T};
         end
         if leftequal
             compareL = " ≤ "
-            compareR = utf8(" < ")
+            compareR = " < "
         else
-            compareL = utf8(" < ")
+            compareL = " < "
             compareR = " ≤ "
         end
         poolindexshift = -1
@@ -458,7 +463,7 @@ end
 #    bounded      gives n-1 categories for n breaks. Values below min or above max will be NA
 function discretize{S<:Real, T<:Real}(x::AbstractArray{S,1}, breaks::Vector{T};
     boundedness = :unbounded,
-    bucketstrs = UTF8String[], # if provided, all of below will be ignored. length must be length(breaks)+1
+    bucketstrs = String[], # if provided, all of below will be ignored. length must be length(breaks)+1
     leftequal=true, # t1 <= x < t2 or t1 < x <= t2?
     absolute=false, # t1 <= |x| < t2?
     rank=true, # add a rank to the string output for easier sorting?
@@ -511,7 +516,7 @@ function discretize{S<:Real, T<:Real}(x::AbstractArray{S,1}, breaks::Vector{T};
 
     if leftequal
         for i in 1:length(x)
-            if isna( x, i )
+            if ismissing( x, i )
                 refs[i] = 0
             elseif x2[i] <  breaks[1]
                 refs[i] = below_min_mult
@@ -529,7 +534,7 @@ function discretize{S<:Real, T<:Real}(x::AbstractArray{S,1}, breaks::Vector{T};
         end
     else
         for i in 1:length(x)
-            if isna( x, i )
+            if ismissing( x, i )
                 refs[i] = 0
             elseif x2[i] < breaks[1]
                 refs[i] = below_min_mult
@@ -579,7 +584,7 @@ end
 # use scale=100.0, suffix="%", to express the quantiles in percentages
 function discretize{S<:Real}(x::AbstractArray{S,1}; quantiles = Float64[], ngroups::Int = 4, kwargs ... )
     if length( quantiles ) != 0
-        if any( _ -> _ < 0.0 || _ > 1.0 , quantiles )
+        if any( x -> x < 0.0 || x > 1.0 , quantiles )
             error( "illegal quantile numbers outside [0,1]")
         end
         if !issorted(quantiles)
@@ -629,12 +634,12 @@ function topnames{S<:AbstractString,T<:Real}( name::AbstractArray{S,1}, measure:
     nr = nrow( dfsorted )
 
     if !absolute
-        pool = UTF8String[]
+        pool = String[]
         refs = fill(zero(DataArrays.DEFAULT_POOLED_REF_TYPE), nr )
         lastval  = zero( T )
         lastrank = 0
         for r in 1:nr
-            if isna( dfsorted[:measure], r )
+            if ismissing( dfsorted[:measure], r )
                 continue
             else
                 val = dfsorted[ r, :measure ]
@@ -663,7 +668,7 @@ function topnames{S<:AbstractString,T<:Real}( name::AbstractArray{S,1}, measure:
         lastval  = zero( T )
         lastrank = 0
         for r in 1:nr
-            if isna( dfsorted[:measure], r )
+            if ismissing( dfsorted[:measure], r )
                 continue
             else
                 val = dfsorted[ r, :measure ]
@@ -684,12 +689,12 @@ function topnames{S<:AbstractString,T<:Real}( name::AbstractArray{S,1}, measure:
         end
         dfsorted[ :rankedflag ] = rankedflag
         dfsorted2 = sort( dfsorted, cols = [ :measure ], rev = [ true ] )
-        rankstr = DataArray(UTF8String,nr)
+        rankstr = DataArray(String,nr)
         rankcount = 1
         lastval  = zero( T )
         lastrank = 0
         for r in 1:nr
-            if isna( dfsorted2[ :measure ], r )
+            if ismissing( dfsorted2[ :measure ], r )
                 continue
             elseif dfsorted2[ r, :rankedflag ]
                 val = dfsorted2[ r, :measure ]
@@ -735,6 +740,6 @@ end
 import DataFrames.describe
 export describe
 
-function describe{T}( io, dv::Array{T,1} )
+function describe{T}( io::IO, dv::Array{T,1} )
     describe( io, DataArray( dv ) )
 end
diff --git a/src/format.jl b/src/format.jl
index 5f30194..12cbeed 100644
--- a/src/format.jl
+++ b/src/format.jl
@@ -9,9 +9,9 @@ type FormatHints
     hidezero      :: Bool
     alternative   :: Bool
     mixedfraction :: Bool
-    suffix        :: UTF8String
+    suffix        :: String
     autoscale     :: Symbol
-    conversion    :: ASCIIString
+    conversion    :: String
 end
 
 function FormatHints{T<:Integer}( ::Type{T} )
@@ -66,7 +66,7 @@ function applyformat{T<:AbstractString}( v::T, fmt::FormatHints )
 end
 
 function applyformat( v::AbstractArray, fmt::FormatHints )
-    strs = UTF8String[]
+    strs = String[]
     for s in v
         push!( strs, applyformat( s, fmt ) )
     end
diff --git a/src/precompile.jl b/src/precompile.jl
index b9d9600..4e17d12 100644
--- a/src/precompile.jl
+++ b/src/precompile.jl
@@ -1,8 +1,8 @@
 precompile( inject, (TwObj{TwTreeData}, Symbol ) )
-precompile( inject, (TwObj{TwTreeData}, ASCIIString ) )
+precompile( inject, (TwObj{TwTreeData}, String ) )
 precompile( inject, (TwObj{TwDfTableData}, Symbol ) )
-precompile( inject, (TwObj{TwDfTableData}, ASCIIString ) )
+precompile( inject, (TwObj{TwDfTableData}, String ) )
 precompile( inject, (TwObj{TwEntryData}, Symbol ) )
-precompile( inject, (TwObj{TwEntryData}, ASCIIString ) )
+precompile( inject, (TwObj{TwEntryData}, String ) )
 precompile( inject, (TwObj{TwScreenData}, Symbol ) )
-precompile( inject, (TwObj{TwScreenData}, ASCIIString ) )
+precompile( inject, (TwObj{TwScreenData}, String ) )
diff --git a/src/readtoken.jl b/src/readtoken.jl
index c17585d..dd3d2d7 100644
--- a/src/readtoken.jl
+++ b/src/readtoken.jl
@@ -1,4 +1,4 @@
-const keymap = Compat.@Dict(
+const keymap = Dict(
     "\eOA"    => :up,
     "\e[1;2A" => :shift_up,
     "\e[1;5A" => :ctrl_up,
@@ -125,7 +125,7 @@ const keymap = Compat.@Dict(
     "\e"*string(@compat Char(0x152)) => :alt_pagedown
 )
 
-ncnummap = Compat.@Dict(
+ncnummap = Dict(
     (@compat UInt(0x7f)) => :backspace,
     (@compat UInt(0x01)) => :ctrl_a,
     (@compat UInt(0x02)) => :ctrl_b,
@@ -305,7 +305,7 @@ ncnummap = Compat.@Dict(
 )
 
 
-const keypadmap = Compat.@Dict(
+const keypadmap = Dict(
     :keypad_dot => ".",
     :keypad_enter => Symbol( "return" ),
     :keypad_asterisk => "*",
@@ -369,39 +369,39 @@ function readtoken( win::Ptr{Void} )
             return string( @compat Char( c ) )
         end
     elseif 192 <= c <= 223 # utf8 based logic starts here
-        bs = Array( UInt8, 2 )
+        bs = Array{UInt8}( 2 )
         bs[1] = @compat UInt8( c )
         bs[2] = @compat UInt8( wgetch( win ) )
-        return convert( UTF8String, bs )
+        return convert( String, bs )
     elseif  224 <= c <= 239
-        bs = Array( UInt8, 3 )
+        bs = Array{UInt8}( 3 )
         bs[1] = @compat UInt8( c )
         bs[2] = @compat UInt8( wgetch( win ) )
         bs[3] = @compat UInt8( wgetch( win ) )
-        return convert( UTF8String, bs )
+        return convert( String, bs )
     elseif  240 <= c <= 247
-        bs = Array( UInt8, 4 )
+        bs = Array{UInt8}( 4 )
         bs[1] = @compat UInt8( c )
         bs[2] = @compat UInt8( wgetch( win ) )
         bs[3] = @compat UInt8( wgetch( win ) )
         bs[4] = @compat UInt8( wgetch( win ) )
-        return convert( UTF8String, bs )
+        return convert( String, bs )
     elseif  248 <= c <= 251
-        bs = Array( UInt8, 5 )
+        bs = Array{UInt8}( 5 )
         bs[1] = @compat UInt8( c )
         bs[2] = @compat UInt8( wgetch( win ) )
         bs[3] = @compat UInt8( wgetch( win ) )
         bs[4] = @compat UInt8( wgetch( win ) )
         bs[5] = @compat UInt8( wgetch( win ) )
-        return convert( UTF8String, bs )
+        return convert( String, bs )
     elseif  252 <= c <= 253
-        bs = Array( UInt8, 6 )
+        bs = Array{UInt8}( 6 )
         bs[1] = @compat UInt8( c )
         bs[2] = @compat UInt8( wgetch( win ) )
         bs[3] = @compat UInt8( wgetch( win ) )
         bs[4] = @compat UInt8( wgetch( win ) )
         bs[5] = @compat UInt8( wgetch( win ) )
         bs[6] = @compat UInt8( wgetch( win ) )
-        return convert( UTF8String, bs )
+        return convert( String, bs )
     end
 end
diff --git a/src/strutils.jl b/src/strutils.jl
index 4cfba2a..4c405e0 100644
--- a/src/strutils.jl
+++ b/src/strutils.jl
@@ -1,5 +1,5 @@
 function repr_symbol( s::Symbol )
-    v = utf8(string(s))
+    v = string(s)
     if length(v) == 0
         v = ":\"\""
     elseif match( r"^[a-zA-Z_][0-9a-zA-Z_]*$", v ) != nothing
@@ -10,12 +10,8 @@ function repr_symbol( s::Symbol )
     v
 end
 
-function delete_char_before( s::ASCIIString, p::Int )
-    return (s[1:p-2] * s[p:end], max(p-1,1) )
-end
-
 #delete a code_point before the p "width" position
-function delete_char_before( s::UTF8String, p::Int )
+function delete_char_before( s::String, p::Int )
     local totalskip::Int = 0
     local lastj::Int = 0
     local lastcw::Int = 0
@@ -46,13 +42,9 @@ function delete_char_before( s::UTF8String, p::Int )
     return (s[1:chr2ind(s,lastj-1)], p-lastcw)
 end
 
-function delete_char_at( s::ASCIIString, p::Int )
-    return s[1:p-1] * s[p+1:end]
-end
-
 # delete at least 1 code point, could be more if there
 # are trailing zero-width codepoints.
-function delete_char_at( s::UTF8String, p::Int )
+function delete_char_at( s::String, p::Int )
     local totalskip::Int = 0
     local lastj::Int = 0
     for (j,c) in enumerate( s )
@@ -75,7 +67,7 @@ end
 # TODO: test this thoroughly!!
 # Insert a (short) string at the "p" position
 # p is interpreted as the width position
-function insertstring{T<:AbstractString}( s::UTF8String, ch::T, p::Int, overwrite::Bool )
+function insertstring{T<:AbstractString}( s::String, ch::T, p::Int, overwrite::Bool )
     wskip = p-1
     local totalskip::Int = 0
     chwidth = strwidth( ch )
@@ -191,7 +183,7 @@ end
 
 function wordwrap{T<:AbstractString}( x::T, width::Int )
     spaceleft = width
-    lines = UTF8String[]
+    lines = String[]
     currline = convert( T,"" )
     words = @compat split( x, " ", keep=true ) # don't keep empty words
     for w in words
@@ -241,7 +233,7 @@ function levenstein_distance( s1, s2 )
     return v1[end]
 end
 
-function longest_common_prefix( s1::UTF8String, s2::UTF8String )
+function longest_common_prefix( s1::String, s2::String )
     m = min( length( s1 ), length( s2 ) )
     lcpidx = 0
     for i in 1:m
diff --git a/src/twcalendar.jl b/src/twcalendar.jl
index 61ad34c..e31490b 100644
--- a/src/twcalendar.jl
+++ b/src/twcalendar.jl
@@ -16,7 +16,7 @@ y,Y    : add/subtract a year
 """
 type TwCalendarData
     showHelp::Bool
-    helpText::UTF8String
+    helpText::String
     date::Date
     cursorweekofmonth::Int # cached "nth week" in the current month containing date, 1-based
     geometry::@compat Tuple{Int, Int} # rows x cols in months
diff --git a/src/twdftable.jl b/src/twdftable.jl
index 4641270..695a493 100644
--- a/src/twdftable.jl
+++ b/src/twdftable.jl
@@ -31,7 +31,7 @@ end
 
 type TwTableColInfo
     name::Symbol
-    displayname::UTF8String
+    displayname::String
     format::FormatHints
     aggr::Any
 end
@@ -64,7 +64,7 @@ function getindex( n::TwDfTableNode, c::Symbol )
         context = n.context.value
         aggr = context.allcolInfo[ c ].aggr
         f = liftAggrSpecToFunc( c, aggr )
-        ret = f( n.subdataframe )
+        ret = Base.invokelatest(f, n.subdataframe )
         if typeof( ret ) <: AbstractDataFrame
             ret = ret[1][1] # first col, first row
         end
@@ -75,7 +75,7 @@ function getindex( n::TwDfTableNode, c::Symbol )
 end
 
 type TwTableView
-    name::UTF8String
+    name::String
     pivots::Array{Symbol,1}
     sortorder::Array{ (@compat Tuple{Symbol,Symbol}), 1 } # [ (:col1, :asc ), (:col2, :desc), ... ]
     columns::Array{ Symbol, 1 }
@@ -83,7 +83,7 @@ type TwTableView
 end
 
 # convenient functions to construct views
-function TwTableView( df::AbstractDataFrame, name::UTF8String;
+function TwTableView( df::AbstractDataFrame, name::String;
     pivots = Symbol[], initdepth=1,
     colorder = Any[ "*" ],
     hidecols = Any[], sortorder = Any[] )
@@ -148,7 +148,7 @@ function TwTableView( df::AbstractDataFrame, name::UTF8String;
         error( "sortorder eltype expects Symbol, or Tuple{Symbol,Symbol}: " * string( eltype( sortorder ) ) )
     end
 
-    TwTableView( utf8(name), pivots, actualsortorder, finalcolorder, initdepth )
+    TwTableView( name, pivots, actualsortorder, finalcolorder, initdepth )
 end
 
 # this is the widget data. all subnodes hold a weakref back to this to
@@ -168,16 +168,16 @@ type TwDfTableData
     currentRight::Int # right most on-screen column
     colInfo::Array{ TwTableColInfo, 1 } # only the visible ones, maybe off-screen
     allcolInfo::Dict{ Symbol, TwTableColInfo } # including invisible ones
-    bottomText::UTF8String
-    helpText::UTF8String
+    bottomText::String
+    helpText::String
     initdepth::Int
     views::Array{ TwTableView, 1 }
     calcpivots::Dict{ Symbol, CalcPivot }
-    searchText::UTF8String
+    searchText::String
     # calculated dimension
     TwDfTableData() = new( TwDfTableNode(),
         Symbol[], Tuple{Symbol,Symbol}[], Any[], 0, 10, 1, 1, 1, 1, 1, 1, TwTableColInfo[],
-        Dict{Symbol,TwTableColInfo}(), "", defaultTableHelpText, 1, TwTableView[], Dict{Symbol,CalcPivot}(),utf8("") )
+        Dict{Symbol,TwTableColInfo}(), "", defaultTableHelpText, 1, TwTableView[], Dict{Symbol,CalcPivot}(),"" )
 end
 
 #TODO: allow Regex in formatHints and aggrHints
@@ -192,7 +192,7 @@ function newTwDfTable( scr::TwObj, df::DataFrame;
         formatHints = Dict{Any,FormatHints}(), # Symbol/Type -> FormatHints
         aggrHints = Dict{Any,Any}(), # Symbol/Type -> string/symbol/expr/function
         widthHints = Dict{Symbol,Int}(),
-        headerHints = Dict{Symbol,UTF8String}(),
+        headerHints = Dict{Symbol,String}(),
         bottomText = defaultTableBottomText,
         views = Dict{Symbol,Any}[],
         calcpivots = Dict{Symbol,CalcPivot}() )
@@ -205,7 +205,7 @@ function newTwDfTable( scr::TwObj, df::DataFrame;
     obj.data.rootnode.subdataframe = df
     obj.data.rootnode.context = WeakRef( obj.data )
 
-    mainV = TwTableView( df, utf8( "#Main"), pivots = pivots,
+    mainV = TwTableView( df, "#Main", pivots = pivots,
         initdepth=initdepth, sortorder=sortorder, colorder=colorder, hidecols=hidecols )
 
     obj.data.pivots = mainV.pivots
@@ -225,7 +225,7 @@ function newTwDfTable( scr::TwObj, df::DataFrame;
         vcolorder = get( d, :colorder, colorder )
         vhidecols = get( d, :hidecols, hidecols )
         vsortorder = get( d, :sortorder, sortorder )
-        v = TwTableView( df, utf8( vname ), pivots = vpivots, initdepth = vinitdepth,
+        v = TwTableView( df, vname, pivots = vpivots, initdepth = vinitdepth,
             sortorder=vsortorder, colorder = vcolorder, hidecols = vhidecols )
         push!( obj.data.views, v )
     end
@@ -292,7 +292,7 @@ function expandnode( n::TwDfTableNode, depth::Int=1 )
                 pvtby   = setdiff( calcpvt.by, npivots )
                 f = liftCalcPivotToFunc( pvtspec, pvtby )
                 if isempty( pvtby )
-                    colvalues = f( n.subdataframe )
+                    colvalues = Base.invokelatest(f, n.subdataframe )
                     # Note that setindex! doesn't work for subdataframe
                     # And we most certainly don't want to mutate the original
                     # dataframe (if the node n here is the rootnode)
@@ -313,7 +313,7 @@ function expandnode( n::TwDfTableNode, depth::Int=1 )
                     # the lifted function expects us to provide
                     # the aggregation spec on all needed columns,
                     # as keyword arguments
-                    df = f( n.subdataframe, nextpivot; kwargs... )
+                    df = Base.invokelatest(f, n.subdataframe, nextpivot; kwargs... )
                     gd = DataFrames.groupby( join( n.subdataframe, df, on=pvtby, kind=:left ), nextpivots )
                 end
             else
@@ -348,13 +348,13 @@ function ordernode( n::TwDfTableNode )
         if length( sortorder ) > 0
             sort!( n.children, lt = (x,y) -> begin
                 for sc in sortorder
-                    if isna( x[sc[1]] )
-                        if !isna( y[sc[1]] )
+                    if ismissing( x[sc[1]] )
+                        if !ismissing( y[sc[1]] )
                             return false
                         else
                             continue
                         end
-                    elseif isna( y[sc[1]] )
+                    elseif ismissing( y[sc[1]] )
                         return true
                     end
                     if x[sc[1]] == y[sc[1]]
@@ -556,7 +556,7 @@ function draw( o::TwObj{TwDfTableData} )
             end
             width = ( col == lastcol ? lastwidth : o.data.colInfo[ col ].format.width )
             isred = false
-            if typeof( v ) == NAtype
+            if typeof( v ) == Missing
                 str = ensure_length( "", width )
             elseif typeof( v ) <: Real
                 str = applyformat( v, o.data.colInfo[col].format )
@@ -954,7 +954,7 @@ function inject( o::TwObj{TwDfTableData}, token )
                 dorefresh = true
             end
             if o.data.datatreewidth+1<relx<o.width-1 && o.data.headerlines<=rely<o.height-1
-                cumwidths = cumsum( map( _->_+1, widths[o.data.currentLeft:end] ) ) # with boundary
+                cumwidths = cumsum( map( x->x+1, widths[o.data.currentLeft:end] ) ) # with boundary
                 widthrng = searchsorted( cumwidths, relx - o.data.datatreewidth - 1)
                 o.data.currentCol = min( length( o.data.colInfo ), o.data.currentLeft + widthrng.start - 1 )
                 checkLeft()
@@ -1035,9 +1035,9 @@ function inject( o::TwObj{TwDfTableData}, token )
             end
         end
     elseif token == "p"
-        allcols = map(_->utf8(string(_)), names( o.data.rootnode.subdataframe ) )
-        append!( allcols, map( _->utf8(string(_)), collect( keys( o.data.calcpivots ) ) ) )
-        pvts = map( _->utf8(string(_)), o.data.pivots )
+        allcols = map(x->string(x), names( o.data.rootnode.subdataframe ) )
+        append!( allcols, map( x->string(x), collect( keys( o.data.calcpivots ) ) ) )
+        pvts = map( x->string(x), o.data.pivots )
         helper = newTwMultiSelect( o.screen.value, allcols, selected = pvts, title="Pivot order", orderable=true, substrsearch=true )
         newpivots = activateTwObj( helper )
         unregisterTwObj( o.screen.value, helper )
@@ -1053,8 +1053,8 @@ function inject( o::TwObj{TwDfTableData}, token )
         end
         dorefresh = true
     elseif token == "c"
-        allcols = map(_->utf8(string(_)), names( o.data.rootnode.subdataframe ) )
-        visiblecols = map( _->utf8(string(_.name)), o.data.colInfo )
+        allcols = map(x->string(x), names( o.data.rootnode.subdataframe ) )
+        visiblecols = map( x->string(x.name), o.data.colInfo )
         helper = newTwMultiSelect( o.screen.value, allcols, selected = visiblecols, title="Visible columns & their order", orderable=true, substrsearch=true )
         newcols = activateTwObj( helper )
         unregisterTwObj( o.screen.value, helper )
@@ -1066,12 +1066,12 @@ function inject( o::TwObj{TwDfTableData}, token )
         end
         dorefresh = true
     elseif token == "v"
-        allviews = map( _->_.name, o.data.views )
+        allviews = map( x->x.name, o.data.views )
         helper = newTwPopup( o.screen.value, allviews, substrsearch=true, title = "Views" )
         vname = activateTwObj( helper )
         unregisterTwObj( o.screen.value, helper )
         if vname != nothing
-            idx = findfirst( _->_.name == vname, o.data.views )
+            idx = findfirst( x->x.name == vname, o.data.views )
             v = o.data.views[idx]
             o.data.colInfo = TwTableColInfo[]
             o.data.pivots = v.pivots
@@ -1090,7 +1090,7 @@ function inject( o::TwObj{TwDfTableData}, token )
             dorefresh=true
         end
     elseif token == "/"
-        helper = newTwEntry( o.screen.value, UTF8String; width=30, posy=:center, posx=:center, title = "Search: " )
+        helper = newTwEntry( o.screen.value, String; width=30, posy=:center, posx=:center, title = "Search: " )
         helper.data.inputText = o.data.searchText
         s = activateTwObj( helper )
         unregisterTwObj( o.screen.value, helper )
@@ -1102,7 +1102,7 @@ function inject( o::TwObj{TwDfTableData}, token )
         end
         dorefresh = true
     elseif token == "?"
-        helper = newTwEntry( o.screen.value, UTF8String; width=30, posy=:center, posx=:center, title = "Search: " )
+        helper = newTwEntry( o.screen.value, String; width=30, posy=:center, posx=:center, title = "Search: " )
         helper.data.inputText = o.data.searchText
         s = activateTwObj( helper )
         unregisterTwObj( o.screen.value, helper )
@@ -1129,7 +1129,7 @@ function inject( o::TwObj{TwDfTableData}, token )
         else
             v = node.subdataframesorted[ colsym ][ o.data.datalist[o.data.currentLine][2][end] ]
         end
-        if typeof( v ) != NAtype && !in( v, [ nothing, Void, Any ] )
+        if typeof( v ) != Missing && !in( v, [ nothing, Void, Any ] )
             tshow( v; title = string( colsym ), posx=:center, posy=:center )
             dorefresh = true
         end
@@ -1143,7 +1143,7 @@ function inject( o::TwObj{TwDfTableData}, token )
             println( out, "\nRoot table stats" )
             describe( out, o.data.rootnode.subdataframe[ colsym ] )
         end
-        tshow( takebuf_string( out ); title = string( colsym )  * " stats", posx=:center,posy=:center)
+        tshow( String( take!(out) ); title = string( colsym )  * " stats", posx=:center,posy=:center)
         dorefresh = true
     else
         retcode = :pass # I don't know what to do with it
diff --git a/src/twentry.jl b/src/twentry.jl
index 877e7f7..ff47e26 100644
--- a/src/twentry.jl
+++ b/src/twentry.jl
@@ -1,6 +1,6 @@
 # hand-crafted numeric and string input field
 
-defaultEntryStringHelpText = utf8("""
+defaultEntryStringHelpText = """
 <-, -> : move cursor
 ctrl-a : move cursor to start
 ctrl-e : move cursor to end
@@ -8,9 +8,9 @@ ctrl-k : empty entry
 ctrl-r : Toggle insertion/overwrite mode
 
 Edges are highlighted if more beyond boundary
-""")
+"""
 
-defaultEntryNumberHelpText = utf8("""
+defaultEntryNumberHelpText = """
 <-, -> : move cursor
 ctrl-a : move cursor to start
 ctrl-e : move cursor to end
@@ -22,9 +22,9 @@ e      : (Floating Point only) exponent. 1e6 for 1,000,000.0
 ctrl-r : Toggle insertion/overwrite mode
 Shft-up: If configured, increase value by a tick-size
 Shft-dn: If configured, decrease value by a tick-size
-""")
+"""
 
-defaultEntryDateHelpText = utf8("""
+defaultEntryDateHelpText = """
 Format : YYYY-MM-DD standard, but allows formats such as
          20140101, 1/1/2014, 1Jan2014, 1 January 2014
          2014.01.01
@@ -37,12 +37,12 @@ ctrl-r : Toggle insertion/overwrite mode
 ?      : View calendar
 Shft-up: If configured, increase value by a tick-size
 Shft-dn: If configured, decrease value by a tick-size
-""")
+"""
 type TwEntryData
     valueType::DataType
     showHelp::Bool
-    helpText::UTF8String
-    inputText::UTF8String
+    helpText::String
+    inputText::String
     cursorPos::Int # where is the next char going to be
     fieldLeftPos::Int # what is the position of the first char on the field
     tickSize::Any
@@ -53,9 +53,9 @@ type TwEntryData
     precision::Int
     commas::Bool
     stripzeros::Bool
-    conversion::ASCIIString
+    conversion::String
     function TwEntryData( dt::DataType )
-        o = new( dt, false, utf8(""), utf8(""), 1, 1, 0, true, false, false, false,
+        o = new( dt, false, "", "", 1, 1, 0, true, false, false, false,
            -1, true, true, "" )
         if dt <: AbstractString
             o.helpText = defaultEntryStringHelpText
@@ -88,7 +88,7 @@ end
 # y and x is relative to parentwin
 function newTwEntry( parent::TwObj, dt::DataType;
     width::Real=30,posy::Any=:staggered,posx::Any=:staggered,
-    box=true, showHelp=true, titleLeft=true, title = utf8(""),
+    box=true, showHelp=true, titleLeft=true, title = "",
     precision=-1, stripzeros= (precision == -1), conversion="" )
 
     data = TwEntryData( dt )
@@ -343,7 +343,7 @@ function inject( o::TwObj{TwEntryData}, token )
         else
             beep()
         end
-    elseif o.data.valueType == Bool && typeof( token ) <: AbstractString && isprint( token )
+    elseif o.data.valueType == Bool && typeof( token ) <: AbstractString && all(isprint, token )
         if token == "t"
             o.data.inputText = "true"
             o.data.cursorPos = 1
@@ -434,7 +434,7 @@ function inject( o::TwObj{TwEntryData}, token )
             insertchar( token )
             dorefresh = true
         end
-    elseif typeof( token ) <: AbstractString && o.data.valueType <: AbstractString && isprint( token )
+    elseif typeof( token ) <: AbstractString && o.data.valueType <: AbstractString && all(isprint, token )
         insertchar( token )
         checkcursor()
         dorefresh = true
@@ -509,6 +509,7 @@ function evalNFormat( data::TwEntryData, s::AbstractString, fieldcount::Int )
             else
                 v = parse( dt, stmp )
             end
+        catch
         end
         if v != nothing
             v = convert(dt, v)
@@ -525,6 +526,7 @@ function evalNFormat( data::TwEntryData, s::AbstractString, fieldcount::Int )
                 else
                     v = parse( dt.types[1], stmp )
                 end
+            catch
             end
             if v != nothing
                 v = convert( dt, v)
@@ -545,6 +547,7 @@ function evalNFormat( data::TwEntryData, s::AbstractString, fieldcount::Int )
                     tail = stmp[dpos+1:end]
                     fv = parse( dt.types[2], tail ) // ( 10 ^ length(tail) )
                 end
+            catch
             end
             if iv != nothing && fv != nothing
                 v = iv + (sign(iv) > 0? fv : -fv )
@@ -560,6 +563,7 @@ function evalNFormat( data::TwEntryData, s::AbstractString, fieldcount::Int )
             else
                 v = parse( dt, stmp )
             end
+        catch
         end
         if v != nothing
             v = convert( dt, v)
@@ -568,7 +572,7 @@ function evalNFormat( data::TwEntryData, s::AbstractString, fieldcount::Int )
     elseif dt <: Date
         v = nothing
         s = strip( s )
-        res = Compat.@Dict( r"^[0-9]{2}[a-z]{3}[0-9]{4}$"i => "dduuuyyyy",
+        res = Dict( r"^[0-9]{2}[a-z]{3}[0-9]{4}$"i => "dduuuyyyy",
                 r"^[0-9][a-z]{3}[0-9]{4}$"i => "duuuyyyy",
                 r"^[0-9]{2}[a-z]{3}[0-9]{2}$"i => "dduuuyy",
                 r"^[0-9][a-z]{3}[0-9]{2}$"i => "duuuyy",
@@ -590,6 +594,7 @@ function evalNFormat( data::TwEntryData, s::AbstractString, fieldcount::Int )
             if m != nothing
                 try
                     v = Date( s, f )
+                catch
                 end
                 if v != nothing
                     fmt = f
@@ -630,7 +635,7 @@ end
 
 function helptext( o::TwObj{TwEntryData} )
     if !o.data.showHelp
-        return utf8("")
+        return ""
     end
     o.data.helpText
 end
diff --git a/src/twfunc.jl b/src/twfunc.jl
index ef97fd9..5d2a529 100644
--- a/src/twfunc.jl
+++ b/src/twfunc.jl
@@ -1,4 +1,4 @@
-defaultFuncHelpText = utf8("""
+defaultFuncHelpText = """
 PgUp/PgDn  : method list navigation
 Up/Dn      : method list navigation
 Left/Right : search term cursor control
@@ -12,7 +12,7 @@ Shift-left/right : Navigate method list left and right
 Ctrl-Sht-lft/rgt : Jump method list to left and right edge
 F6         : explore Method as tree
 F8         : edit method
-""")
+"""
 
 type TwFuncData
     datalist::Array{Any,1}
@@ -23,24 +23,32 @@ type TwFuncData
     currentLine::Int
     currentLeft::Int
     showLineInfo::Bool # e.g.1/100 1.0% at top right corner
-    bottomText::UTF8String
+    bottomText::String
     showHelp::Bool
-    helpText::UTF8String
+    helpText::String
     TwFuncData() = new( Method[], 0, 0, nothing,
-        1, 1, 1, true, utf8(""), true, defaultFuncHelpText )
+        1, 1, 1, true, "", true, defaultFuncHelpText )
+end
+
+function argName(s, n)
+    try
+        return s.types[n]
+    catch
+        return argName(s.body, n)
+    end
 end
 
 # the ways to use it:
 # exact dimensions known: h,w,y,x, content to add later
 # exact dimensions unknown, but content known and content drives dimensions
 function newTwFunc( scr::TwObj, ms::Array{Method,1}; kwargs... )
-    ns = UTF8String[] # names
-    sig  = UTF8String[]
-    files = UTF8String[]
+    ns = String[] # names
+    sig  = String[]
+    files = String[]
     lines = Int[]
     for m in ms
-        push!( ns, utf8( string( m.func.code.name ) ) )
-        push!( sig, utf8( string( m.sig ) ) )
+        push!( ns, string( m.name ) )
+        push!( sig, string( m.sig ) )
         tv, decls, file, line = Base.arg_decl_parts(m)
         push!( files, string( file ) )
         push!( lines, line )
@@ -50,10 +58,10 @@ function newTwFunc( scr::TwObj, ms::Array{Method,1}; kwargs... )
           sig = sig,
           file = files,
           line = lines,
-          nargs = Int[ length(m.sig) for m in ms ],
-          arg1t = UTF8String[ (length(m.sig)>=1 ? ensure_length(utf8(m.sig[1]),35,false) : "") for m in ms ],
-          arg2t = UTF8String[ (length(m.sig)>=2 ? ensure_length(utf8(m.sig[2]),35,false) : "") for m in ms ],
-          arg3t = UTF8String[ (length(m.sig)>=3 ? ensure_length(utf8(m.sig[3]),35,false) : "") for m in ms ]
+          nargs = Int[ m.nargs for m in ms ],
+          arg1t = String[ (m.nargs>=1 ? ensure_length(string(argName(m.sig,1)),35,false) : "") for m in ms ],
+          arg2t = String[ (m.nargs>=2 ? ensure_length(string(argName(m.sig,2)),35,false) : "") for m in ms ],
+          arg3t = String[ (m.nargs>=3 ? ensure_length(string(argName(m.sig,3)),35,false) : "") for m in ms ]
           )
     colorder = extractkwarg!( kwargs, :colorder, [ :name, :sig, :nargs, "*" ] )
     pivots   = extractkwarg!( kwargs, :pivots, [ ] )
diff --git a/src/twlist.jl b/src/twlist.jl
index 3f05488..41a8d7c 100644
--- a/src/twlist.jl
+++ b/src/twlist.jl
@@ -14,7 +14,7 @@ function newTwList( scr::TwObj;
         canvaswidth = 128,
         box=true,
         horizontal=false,
-        title=utf8(""),
+        title="",
         showLineInfo=true)
     obj = TwObj( TwListData(), Val{:List } )
     obj.box = box
@@ -85,11 +85,11 @@ function update_list_canvas( o::TwObj{TwListData} )
             end
         end
         if o.data.horizontal
-            o.data.canvasheight = maximum( map( _->objtype(_)==:List? _.data.canvasheight : _.height, ws ) )
-            o.data.canvaswidth = sum( map( _->objtype(_)==:List? _.data.canvaswidth : _.width, ws ) )
+            o.data.canvasheight = maximum( map( x->objtype(x)==:List? x.data.canvasheight : x.height, ws ) )
+            o.data.canvaswidth = sum( map( x->objtype(x)==:List? x.data.canvaswidth : x.width, ws ) )
         else
-            o.data.canvasheight = sum( map( _->objtype(_)==:List? _.data.canvasheight: _.height, ws ) )
-            o.data.canvaswidth = maximum( map( _->objtype(_)==:List? _.data.canvaswidth : _.width, ws ) )
+            o.data.canvasheight = sum( map( x->objtype(x)==:List? x.data.canvasheight: x.height, ws ) )
+            o.data.canvaswidth = maximum( map( x->objtype(x)==:List? x.data.canvaswidth : x.width, ws ) )
         end
         if !(typeof( o.window ) <: Ptr)
             o.height = o.data.canvasheight + (o.box?2:0)
@@ -632,17 +632,17 @@ function helptext( o::TwObj{TwListData} )
     focus = o.data.focus
     isrootlist = typeof( o.window ) <: Ptr
     if focus == 0
-        return utf8("")
+        return ""
     end
     s = helptext( o.data.widgets[ focus ] )
     if isrootlist
-h = utf8("""
+h = """
 ctrl-F4 : toggle navigation mode
 mouse-click: activate nearest widget
 ctrl-arrows: directional focus movements
   (normal arrows work too if not consumed by the current widget)
 tab/shift-tab: cycle through all widgets
-""")
+"""
         if s == "" # just the navigation text
             s = h
         else # merge the help text into a single window
diff --git a/src/twmultiselect.jl b/src/twmultiselect.jl
index 1cdc418..21e8e03 100644
--- a/src/twmultiselect.jl
+++ b/src/twmultiselect.jl
@@ -3,7 +3,7 @@
 SELECTEDORDERABLE    = 1 # whether selected items are orderable, selected always on top
 SELECTSUBSTR         = 2 # search by substring (default by prefix)
 
-defaultMultiSelectHelpText = utf8("""
+defaultMultiSelectHelpText = """
 arrows : move cursor
 home   : move to top
 end    : move to bottom
@@ -21,11 +21,11 @@ ctrl-r : Toggle insertion/overwrite mode
 
 ctrl-n : move to the next matched item
 ctrl-p : move to the previous matched item
-""")
+"""
 
 type TwMultiSelectData
-    choices::Array{UTF8String,1}
-    selected::Array{UTF8String,1}
+    choices::Array{String,1}
+    selected::Array{String,1}
     datalist::Array{Any, 1}
     maxchoicelength::Int
     searchbox::Any
@@ -33,10 +33,10 @@ type TwMultiSelectData
     currentLeft::Int
     currentTop::Int
     selectmode::Int
-    helpText::UTF8String
-    TwMultiSelectData( arr::Array{UTF8String,1}, selected::Array{UTF8String,1} ) = new( arr, selected, Any[], 0, nothing, 1, 1, 1, 0, utf8("") )
+    helpText::String
+    TwMultiSelectData( arr::Array{String,1}, selected::Array{String,1} ) = new( arr, selected, Any[], 0, nothing, 1, 1, 1, 0, "" )
 end
-TwMultiSelectData{T<:AbstractString,T2<:AbstractString}( arr::Array{T,1}, selected::Array{T2,1} ) = TwMultiSelectData( map( x->utf8( x ), arr ), map( x->utf8(x), selected ) )
+TwMultiSelectData{T<:AbstractString,T2<:AbstractString}( arr::Array{T,1}, selected::Array{T2,1} ) = TwMultiSelectData( map( x->x , arr ), map( x->x, selected ) )
 
 # the ways to use it:
 # standalone panel
@@ -44,10 +44,10 @@ TwMultiSelectData{T<:AbstractString,T2<:AbstractString}( arr::Array{T,1}, select
 # w include title width, if it's shown on the left
 function newTwMultiSelect{T<:AbstractString}( scr::TwObj, arr::Array{T,1};
         posy::Any = :center,posx::Any = :center,
-        selected = UTF8String[],
-        title = utf8(""), maxwidth = 50, maxheight = 20, minwidth = 25,
+        selected = String[],
+        title = "", maxwidth = 50, maxheight = 20, minwidth = 25,
         orderable = false, substrsearch=false )
-    obj = TwObj( TwMultiSelectData( arr, UTF8String[ utf8(string(_)) for _ in selected ] ), Val{ :MultiSelect } )
+    obj = TwObj( TwMultiSelectData( arr, String[ string(x) for x in selected ] ), Val{ :MultiSelect } )
     obj.box = true
     obj.title = title
     obj.borderSizeV= 1
@@ -62,7 +62,7 @@ function newTwMultiSelect{T<:AbstractString}( scr::TwObj, arr::Array{T,1};
     obj.data.helpText = defaultMultiSelectHelpText
     obj.data.maxchoicelength = 0
     if !isempty(arr)
-        obj.data.maxchoicelength = maximum( map(_->length(_), arr ) )
+        obj.data.maxchoicelength = maximum( map(x->length(x), arr ) )
     end
 
     h = 2 + min( length( arr ), maxheight )
@@ -70,8 +70,8 @@ function newTwMultiSelect{T<:AbstractString}( scr::TwObj, arr::Array{T,1};
 
     link_parent_child( scr, obj, h,w, posy, posx )
 
-    obj.data.searchbox = newTwEntry( obj, UTF8String, width=minwidth, posy=:bottom, posx=1, box=false )
-    obj.data.searchbox.title = utf8("?")
+    obj.data.searchbox = newTwEntry( obj, String, width=minwidth, posy=:bottom, posx=1, box=false )
+    obj.data.searchbox.title = "?"
     obj.data.searchbox.hasFocus = false
     obj
 end
diff --git a/src/twobj.jl b/src/twobj.jl
index 4813f6e..b2173ed 100644
--- a/src/twobj.jl
+++ b/src/twobj.jl
@@ -263,4 +263,4 @@ end
 
 refresh( o::TwObj ) = (erase(o);draw(o))
 
-helptext( _::TwObj ) = utf8("")
+helptext( _::TwObj ) = ""
diff --git a/src/twpopup.jl b/src/twpopup.jl
index 67f7eb4..9c3aa6c 100644
--- a/src/twpopup.jl
+++ b/src/twpopup.jl
@@ -19,14 +19,14 @@ POPUPHIDEUNMATCHED  = 4
 POPUPSORTMATCHED    = 8
 POPUPALLOWNEW       = 16
 
-defaultPopupHelpText = utf8("""
+defaultPopupHelpText = """
 arrows : move cursor
 home   : move to top
 end    : move to bottom
 enter  : select
-""")
+"""
 
-defaultPopupQuickHelpText = utf8("""
+defaultPopupQuickHelpText = """
 arrows : move item cursor
 home   : move to top
 end    : move to bottom
@@ -40,10 +40,10 @@ ctrl-r : Toggle insertion/overwrite mode
 
 ctrl-n : move to the next matched item
 ctrl-p : move to the previous matched item
-""")
+"""
 
 type TwPopupData
-    choices::Array{UTF8String,1}
+    choices::Array{String,1}
     datalist::Array{Any, 1}
     maxchoicelength::Int
     searchbox::Any
@@ -51,10 +51,10 @@ type TwPopupData
     currentLeft::Int
     currentTop::Int
     selectmode::Int
-    helpText::UTF8String
-    TwPopupData( arr::Array{UTF8String,1} ) = new( arr, Any[], maximum( map( z->length(z), arr ) ), nothing, 1, 1, 1, 0, utf8("") )
+    helpText::String
+    TwPopupData( arr::Array{String,1} ) = new( arr, Any[], maximum( map( z->length(z), arr ) ), nothing, 1, 1, 1, 0, "" )
 end
-TwPopupData{ T<:AbstractString}( arr::Array{T, 1 } ) = TwPopupData( map( x->utf8( x ), arr ) )
+TwPopupData{ T<:AbstractString}( arr::Array{T, 1 } ) = TwPopupData( map( x-> x , arr ) )
 
 # the ways to use it:
 # standalone panel
@@ -62,10 +62,10 @@ TwPopupData{ T<:AbstractString}( arr::Array{T, 1 } ) = TwPopupData( map( x->utf8
 # w include title width, if it's shown on the left
 function newTwPopup( scr::TwObj, arr::Array{Symbol,1};
         posy::Any=:center,posx::Any=:center,
-        title = utf8(""), maxwidth = 50, maxheight = 15, minwidth = 20,
+        title = "", maxwidth = 50, maxheight = 15, minwidth = 20,
         quickselect = false, substrsearch=false, hideunmatched=false, sortmatched=false, allownew=false )
 
-    return( newTwPopup( scr, map(x->utf8(string(x)),arr),
+    return( newTwPopup( scr, map(x->string(x),arr),
         posy=posy,posx=posx,
         title=title,maxwidth=maxwidth,maxheight=maxheight,minwidth=minwidth,
         quickselect=quickselect,substrsearch=substrsearch,
@@ -74,7 +74,7 @@ end
 
 function newTwPopup{T<:AbstractString}( scr::TwObj, arr::Array{T,1};
         posy::Any=:center,posx::Any=:center,
-        title = utf8(""), maxwidth = 50, maxheight = 15, minwidth = 20,
+        title = "", maxwidth = 50, maxheight = 15, minwidth = 20,
         quickselect = false, substrsearch=false, hideunmatched=false, sortmatched=false, allownew=false )
     obj = TwObj( TwPopupData(arr), Val{ :Popup } )
     obj.box = true
@@ -111,8 +111,8 @@ function newTwPopup{T<:AbstractString}( scr::TwObj, arr::Array{T,1};
 
     link_parent_child( scr, obj, h, w, posy, posx )
 
-    obj.data.searchbox = newTwEntry( obj, UTF8String; width=minwidth, posy=:bottom, posx = 1, box=false )
-    obj.data.searchbox.title = utf8("?")
+    obj.data.searchbox = newTwEntry( obj, String; width=minwidth, posy=:bottom, posx = 1, box=false )
+    obj.data.searchbox.title = "?"
     obj.data.searchbox.hasFocus = false # so it looks dimmer than main cursor
     obj
 end
diff --git a/src/twprogress.jl b/src/twprogress.jl
index 41ed9b9..fad2337 100644
--- a/src/twprogress.jl
+++ b/src/twprogress.jl
@@ -6,11 +6,11 @@ type TwProgressData
     progress::Float64
     showProgress::Bool
     cursorPos::Int # where is the progress bar cursor
-    text::UTF8String
+    text::String
     redrawTime::Float64
     statusTime::Float64
     startTime::Float64
-    TwProgressData() = new( RemoteRef(), RemoteRef(), 0.0, true, 1, utf8(""), time(), time(), time() )
+    TwProgressData() = new( RemoteRef(), RemoteRef(), 0.0, true, 1, "", time(), time(), time() )
 end
 
 twGlobProgressData = TwProgressData()
@@ -23,7 +23,7 @@ function updateProgressChannel( status::Symbol, v::Any )
     put!( twGlobProgressData.statusChannel, ( status, v ) )
 end
 
-function progressMessage( s::UTF8String )
+function progressMessage( s::String )
     global twGlobProgressData
     st = :normal
     val = nothing
@@ -34,11 +34,11 @@ function progressMessage( s::UTF8String )
         end
     end
     if typeof( val ) <: Dict && eltype( val ) <: (Symbol, Any)
-        val[ :message ] = utf8(s)
+        val[ :message ] = s
         put!( twGlobProgressData.statusChannel, ( st, val ) )
     else
         if st != :error && st != :done
-            put!( twGlobProgressData.statusChannel, (st, @compat Dict{Symbol,Any}( :message => utf8(s) ) ) )
+            put!( twGlobProgressData.statusChannel, (st, @compat Dict{Symbol,Any}( :message => s ) ) )
         end
     end
 end
@@ -68,9 +68,9 @@ end
 # w include title width, if it's shown on the left
 # the function f takes no argument. It's started right-away
 # the function can call
-# * TermWin.progressMessage( s::UTF8String ) # make sure height can accommodate the content
+# * TermWin.progressMessage( s::String ) # make sure height can accommodate the content
 # * TermWin.progressUpdate( n::Float64 ) # 0.0 <= n <= 1.0
-function newTwProgress( scr::TwObj; height::Real=5, width::Real=40, posy::Any=:center,posx::Any=:center, box=true, title = utf8("") )
+function newTwProgress( scr::TwObj; height::Real=5, width::Real=40, posy::Any=:center,posx::Any=:center, box=true, title = "" )
     global twGlobProgressData
     obj = TwObj( TwProgressData(), Val{ :Progress } )
     obj.data = twGlobProgressData
@@ -119,7 +119,7 @@ function inject( o::TwObj{TwProgressData}, token::Any )
         if st == :init
             twGlobProgressData.startTime = t
             twGlobProgressData.progress = 0.0
-            twGlobProgressData.text = utf8( "init" * strftime( " %H:%M:%S", time() )  )
+            twGlobProgressData.text = "init" * strftime( " %H:%M:%S", time() )
         elseif st == :error
             o.value = val
             retcode = :exit_nothing
@@ -129,11 +129,11 @@ function inject( o::TwObj{TwProgressData}, token::Any )
         else
             if typeof( val ) <: Dict && eltype( val ) <: (Symbol,Any)
                 if haskey( val, :message ) && typeof( val[:message] ) <: AbstractString
-                    twGlobProgressData.text = utf8( val[ :message ] )
+                    twGlobProgressData.text = val[ :message ] 
                 end
                 if haskey( val, :progress ) && typeof( val[ :progress ] ) == Float64
                     twGlobProgressData.progress = val[ :progress ]
-                    #twGlobProgressData.text = utf8( string( st ) * strftime( " %H:%M:%S", time() ) )
+                    #twGlobProgressData.text = string( st ) * strftime( " %H:%M:%S", time() )
                 end
             end
             dorefresh = true
diff --git a/src/twtree.jl b/src/twtree.jl
index 49bf8a2..2bd164e 100644
--- a/src/twtree.jl
+++ b/src/twtree.jl
@@ -1,4 +1,4 @@
-defaultTreeHelpText = utf8("""
+defaultTreeHelpText = """
 PgUp/PgDn,
 Arrow keys : standard navigation
 <spc>,<rtn>: toggle leaf expansion
@@ -12,14 +12,14 @@ F6         : popup window for value
     Shift-F6   : popup window for type
             n, p       : Move to next/previous matched line
             m          : (Module Only) toggle export-only vs all names
-""")
+"""
 
 modulenames = Dict{ Module, Array{ Symbol, 1 } }()
 moduleallnames = Dict{ Module, Array{ Symbol, 1 } }()
 typefields  = Dict{ Any, Array{ Symbol, 1 } }()
 
 typefields[ Method ] = [ :sig, :isstaged ]
-typefields[ VERSION < v"0.5-" ? LambdaStaticData : LambdaInfo ] = [ :name, :module, :file, :line ]
+#typefields[ VERSION < v"0.5-" ? LambdaStaticData : LambdaInfo ] = [ :name, :module, :file, :line ]
 typefields[ DataType ] = [ :name, :super, Symbol( "abstract" ), :mutable, :parameters ]
 typefields[ TypeName ] = [ :name, :module, :primary ]
 
@@ -37,23 +37,23 @@ type TwTreeData
     currentLine::Int
     currentLeft::Int
     showLineInfo::Bool # e.g.1/100 1.0% at top right corner
-    bottomText::UTF8String
+    bottomText::String
     showHelp::Bool
-    helpText::UTF8String
-    searchText::UTF8String
+    helpText::String
+    searchText::String
     moduleall::Bool
     function TwTreeData()
         log( "TwTreeData 0")
         rv = new( Dict{ Any, Bool }(), Any[], 0, 0, 0, 0, 1, 1, 1, true,
-            utf8(""), true, utf8(defaultTreeHelpText), utf8(""), true )
+            "", true, defaultTreeHelpText, "", true )
         log( "TwTreeData 1")
         return( rv )
     end
 end
 
 function newTwTree( scr::TwObj, ex; height::Real=0.8,width::Real=0.8,posy::Any=:staggered, posx::Any=:staggered,
-        title::UTF8String = utf8( string( typeof( ex ) ) ), box::Bool=true, showLineInfo::Bool=true, showHelp::Bool=true,
-        bottomText::UTF8String = utf8("") )
+        title::String = string( typeof( ex ) ), box::Bool=true, showLineInfo::Bool=true, showHelp::Bool=true,
+        bottomText::String = "" )
     log( "newTwTree 0")
     obj = TwObj( TwTreeData(), Val{ :Tree } )
     log( "newTwTree 1")
@@ -80,7 +80,7 @@ end
 # skiplines are hints where we should not draw the vertical lines to the left
 # because it corresponds the end of some list at a lower depth level
 
-function tree_data{T}( x::Any, name::UTF8String, list::Array{T,1}, openstatemap::Dict{ Any, Bool }, stack::Array{Any,1}, skiplines::Array{Int,1}=Int[], moduleall::Bool = true )
+function tree_data{T}( x::Any, name::String, list::Array{T,1}, openstatemap::Dict{ Any, Bool }, stack::Array{Any,1}, skiplines::Array{Int,1}=Int[], moduleall::Bool = true )
     global modulenames, typefields
     isexp = haskey( openstatemap, stack ) && openstatemap[ stack ]
     typx = typeof( x )
@@ -141,7 +141,7 @@ function tree_data{T}( x::Any, name::UTF8String, list::Array{T,1}, openstatemap:
                 subname = "[" * repeat( " ", szdigits - length(istr)) * istr * "]"
                 newstack = copy( stack )
                 push!( newstack, i )
-                intern_tree_data( a, utf8(subname), newstack, i==len )
+                intern_tree_data( a, subname, newstack, i==len )
             end
         end
     elseif typx <: Associative
@@ -167,7 +167,7 @@ function tree_data{T}( x::Any, name::UTF8String, list::Array{T,1}, openstatemap:
                 end
                 newstack = copy( stack )
                 push!( newstack, k )
-                intern_tree_data( v, utf8(subname), newstack, i==len )
+                intern_tree_data( v, subname, newstack, i==len )
             end
         end
     elseif typx == Function
@@ -187,7 +187,7 @@ function tree_data{T}( x::Any, name::UTF8String, list::Array{T,1}, openstatemap:
                 subname = "Method[" * repeat( " ", szdigits - length(istr)) * istr * "]"
                 newstack = copy( stack )
                 push!( newstack, i )
-                intern_tree_data( m, utf8(subname), newstack, i==len )
+                intern_tree_data( m, subname, newstack, i==len )
             end
         end
     elseif typx == Module && !isempty( stack ) # don't want to recursively descend
@@ -225,6 +225,7 @@ function tree_data{T}( x::Any, name::UTF8String, list::Array{T,1}, openstatemap:
                     if length(ns) > 20
                         sort!(ns)
                     end
+                catch
                 end
                 typefields[ typx ] = ns
             end
@@ -237,7 +238,7 @@ function tree_data{T}( x::Any, name::UTF8String, list::Array{T,1}, openstatemap:
         push!( list, (s, t, v, stack, expandhint, skiplines ) )
         if isexp && !isempty( ns )
             for (i,n) in enumerate(ns)
-                subname = utf8(string(n))
+                subname = string(n)
                 newstack = copy( stack )
                 push!( newstack, n )
                 try
@@ -377,7 +378,7 @@ function inject( o::TwObj{TwTreeData}, token )
 
     update_tree_data = ()->begin
         o.data.datalist = Any[]
-        tree_data( o.value, utf8(o.title), o.data.datalist, o.data.openstatemap, Any[], Int[], o.data.moduleall )
+        tree_data( o.value, o.title, o.data.datalist, o.data.openstatemap, Any[], Int[], o.data.moduleall )
         updateTreeDimensions(o)
         viewContentWidth = o.data.datatreewidth + o.data.datatypewidth+o.data.datavaluewidth + 2
     end
@@ -650,7 +651,7 @@ function inject( o::TwObj{TwTreeData}, token )
             beep()
         end
     elseif token == "/"
-        helper = newTwEntry( o.screen.value, UTF8String; width=30, posy=:center, posx=:center, title = "Search: " )
+        helper = newTwEntry( o.screen.value, String; width=30, posy=:center, posx=:center, title = "Search: " )
         helper.data.inputText = o.data.searchText
         s = activateTwObj( helper )
         unregisterTwObj( o.screen.value, helper )
@@ -707,6 +708,6 @@ function helptext( o::TwObj{TwTreeData} )
     if o.data.showHelp
         o.data.helpText
     else
-        utf8("")
+        ""
     end
 end
diff --git a/src/twtypes.jl b/src/twtypes.jl
index 54883d7..9a2fe86 100644
--- a/src/twtypes.jl
+++ b/src/twtypes.jl
@@ -39,16 +39,16 @@ type TwObj{T,S}
     isVisible::Bool
     data::T
     value::Any # the logical "content" that this object contains (return value if editable)
-    title::UTF8String
+    title::String
     listeners::Dict{ Symbol, Array } # event=>array of registered listeners. each listener is of the type (o, ev)->Void
-    function TwObj( data::T )
+    function TwObj{T,S}( data::T ) where {T,S}
         log( "TwObj datatype=" * string( T ) * " TwObjSubtype="*string(S) )
         x = new( WeakRef(), 0,
             nothing,
             nothing,
             0, 0, 0, 0,
             false, 0, 0,
-            true, true, false, true, data, nothing, utf8(""), Dict{Symbol, Array{Function,1} }() )
+            true, true, false, true, data, nothing, "", Dict{Symbol, Array{Function,1} }() )
         finalizer( x, y->begin
             global rootwin
             if y.panel != nothing
@@ -87,9 +87,9 @@ type TwListData
     canvaslocy::Int # 0-based
     showLineInfo::Bool
     navigationmode::Bool
-    bottomText::UTF8String
+    bottomText::String
     function TwListData()
-        ret = new( false, TwObj[], 0, 0, 0, nothing, 0, 0, false, false, utf8("") )
+        ret = new( false, TwObj[], 0, 0, 0, nothing, 0, 0, false, false, "" )
         finalizer( ret, y->begin
             if y.pad != nothing
                 delwin( y.pad )
@@ -99,7 +99,7 @@ type TwListData
     end
 end
 
-typealias TwScreen TwObj{TwScreenData}
+const TwScreen = TwObj{TwScreenData}
 
 function TwObj{T,S}( d::T, ::Type{Val{S}} ) 
     return( TwObj{T,S}(d) )
diff --git a/src/twviewer.jl b/src/twviewer.jl
index bea7634..c4867d8 100644
--- a/src/twviewer.jl
+++ b/src/twviewer.jl
@@ -16,12 +16,12 @@ type TwViewerData
     currentLine::Int
     currentLeft::Int
     showLineInfo::Bool # e.g.1/100 1.0% at top right corner
-    bottomText::UTF8String
+    bottomText::String
     trackLine::Bool
     showHelp::Bool
-    helpText::UTF8String
+    helpText::String
     tabWidth::Int
-    TwViewerData() = new( UTF8String[], 0, 0, 1, 1, 1, true, "", false, true, defaultViewerHelpText, 4 )
+    TwViewerData() = new( String[], 0, 0, 1, 1, 1, true, "", false, true, defaultViewerHelpText, 4 )
 end
 
 # the ways to use it: