Simpler clearfix #2 http://nicolasgallagher.com/micro-clearfix-hack/

bootstrap-1.0.0.css

@@ -6,7 +6,7 @@
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Designed and built with all the love in the world @twitter by @mdo and @fat.
- * Date: Fri Aug 19 19:51:25 PDT 2011
+ * Date: Fri Aug 19 20:19:39 PDT 2011
  */
 /* Reset.less
  * Props to Eric Meyer (meyerweb.com) for his CSS reset file. We're using an adapted version here	that cuts out some of the reset HTML elements we will never need here (i.e., dfn, samp, etc).
@@ -98,12 +98,12 @@ aside {
 .clearfix {
   zoom: 1;
 }
+.clearfix:before, .clearfix:after {
+  display: table;
+  content: "";
+}
 .clearfix:after {
-  display: block;
-  visibility: hidden;
-  height: 0;
   clear: both;
-  content: ".";
 }
 .center-block {
   display: block;
@@ -114,12 +114,12 @@ aside {
   margin: 0 auto;
   zoom: 1;
 }
+.container:before, .container:after {
+  display: table;
+  content: "";
+}
 .container:after {
-  display: block;
-  visibility: hidden;
-  height: 0;
   clear: both;
-  content: ".";
 }
 /*
  * Scaffolding
@@ -128,12 +128,12 @@ aside {
 .row {
   zoom: 1;
 }
+.row:before, .row:after {
+  display: table;
+  content: "";
+}
 .row:after {
-  display: block;
-  visibility: hidden;
-  height: 0;
   clear: both;
-  content: ".";
 }
 .row .span1 {
   float: left;
@@ -355,12 +355,12 @@ div.container-fluid {
   padding: 20px;
   zoom: 1;
 }
+div.container-fluid:before, div.container-fluid:after {
+  display: table;
+  content: "";
+}
 div.container-fluid:after {
-  display: block;
-  visibility: hidden;
-  height: 0;
   clear: both;
-  content: ".";
 }
 div.container-fluid div.sidebar {
   float: left;
@@ -1448,12 +1448,15 @@ ul.tabs, ul.pills {
   padding: 0;
   zoom: 1;
 }
+ul.tabs:before,
+ul.pills:before,
+ul.tabs:after,
+ul.pills:after {
+  display: table;
+  content: "";
+}
 ul.tabs:after, ul.pills:after {
-  display: block;
-  visibility: hidden;
-  height: 0;
   clear: both;
-  content: ".";
 }
 ul.tabs li, ul.pills li {
   display: inline;
@@ -1609,12 +1612,12 @@ div.modal .modal-footer {
   box-shadow: inset 0 1px 0 #ffffff;
   zoom: 1;
 }
+div.modal .modal-footer:before, div.modal .modal-footer:after {
+  display: table;
+  content: "";
+}
 div.modal .modal-footer:after {
-  display: block;
-  visibility: hidden;
-  height: 0;
   clear: both;
-  content: ".";
 }
 div.modal .modal-footer .btn {
   float: right;

lib/preboot.less

@@ -54,15 +54,15 @@
 // MIXINS
 // ------
 
-// Clearfix for clearing floats like a boss
+// Clearfix for clearing floats like a boss h5bp.com/q
 .clearfix {
   zoom: 1;
+	&:before, &:after {
+    display: table;
+    content: "";
+	}
 	&:after {
-    display: block;
-    visibility: hidden;
-    height: 0;
     clear: both;
-    content: ".";
 	}
 }