Emacs

It is possible to use the Julia LanguageServer in Emacs using the lsp-mode and the lsp-julia packages. See the README of lsp-julia to get it working. It also might be helpful to look at this discourse post from @ffevotte to get an idea of the capabilities available.

Alternatives

The following is my (@non-Jedi) config for using LanguageServer.jl with eglot. I haven't tested it much, and there may be weirdness/dragons here I'm not aware of, but you can base your own config on it if interested.

(require 'cl-generic)

(defcustom julia-default-depot ""
  "The default depot path, used if `JULIA_DEPOT_PATH' is unset"
  :type 'string
  :group 'julia-config)

(defcustom julia-default-environment "~/.julia/environment/v1.1"
  "The default julia environment"
  :type 'string
  :group 'julia-config)

(defun julia/get-depot-path ()
  (or (getenv "JULIA_DEPOT_PATH") julia-default-depot))

;; Make project.el aware of Julia projects
(defun julia/project-try (dir)
  (let ((root (or (locate-dominating-file dir "JuliaProject.toml")
                 (locate-dominating-file dir "Project.toml"))))
    (and root (cons 'julia root))))
(add-hook 'project-find-functions 'julia/project-try)
(cl-defmethod project-roots ((project (head julia)))
  (list (cdr project)))

(defun julia/get-environment (dir)
  (if dir (or (locate-dominating-file dir "JuliaProject.toml")
              (locate-dominating-file dir "Project.toml")
              (expand-file-name julia-default-environment))
    (expand-file-name julia-default-environment)))

;; Setup eglot with julia
(with-eval-after-load 'eglot
  (add-to-list 'eglot-server-programs
               ;; function instead of strings to find project dir at runtime
			   '(julia-mode . (lambda (interactive)
                                `("julia"
                                  ,(expand-file-name
                                    "~/.emacs.d/lisp/eglot-julia/eglot.jl")
                                  ,(julia/get-environment (buffer-file-name))
                                  ,(julia/get-depot-path))))))

(add-hook 'julia-mode-hook 'eglot-ensure)

~/.emacs.d/lisp/eglot-julia/eglot.jl is just:

import Pkg
Pkg.activate(@__DIR__)

using LanguageServer, Sockets, SymbolServer

server = LanguageServer.LanguageServerInstance(stdin, stdout, false,
                                               ARGS[1], ARGS[2], Dict())
server.runlinter = true
run(server)

with the following Project.toml:

[deps]
LanguageServer = "2b0e0bc5-e4fd-59b4-8912-456d1b03d8d7"
Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
SymbolServer = "cf896787-08d5-524d-9de7-132aaa0cb996"