For terminal users, the available editors are as follows:
Vim together with
Julia-vimworks great (https://github.com/JuliaLang/julia-vim)Emacs with
julia-mode.elfrom the https://github.com/JuliaLang/julia/tree/master/contrib directory
On Linux, gedit is very good. The Julia plugin works well and provides autocompletion. Notepad++ also has Julia support from the contrib directory mentioned earlier.
The SageMath project (https://cloud.sagemath.com/) runs Julia in the cloud within a terminal and lets you work with IPython notebooks. You can also work and teach with Julia in the cloud using the JuliaBox platform (https://juliabox.org/).