Back in February I wrote about Atom. At the time, I felt Atom showed promise, but was still a bit lacking. After Github announced that Atom is now completely open source in May, I decided to take another look. Most of what I use every day for development is open source, especially the tools with which I make my living: Linux, zsh, Ruby, Rails, etc that I find the idea of my editor being open source very appealing.
Atom uses ctags, as does other Unix-y editors. Support for jumping back from declarations has now been added, wich was crucial for my workflow. Another issue I had was the lack of context when multiple symbols were listed when navigating, but I managed to wrestle my way through coffeescript to fix that. Now, it works just like I expect it to.
Atom has much better performance now and it is clear that the development team consider this a priority. Overall, I find that the speed while working in the editor (opening files, editing files, jumping between files, searching) is acceptable and I do not notice and lag. Opening the editor, however is another matter. It is very sluggish, even when opening directories that are not deep and with a small number of files. For example, I enjoy using Atom for my git commit messages since I am already familiar with the navigation and it has a nice syntax formatting. However, some times it takes several seconds to open and makes me want to tear my hair out.
apm to download a package, make a few fixes and submit a pull request: I can see why there is so much excitement about Atom.
I have been using Atom as my main editor for the last 3 months. For being a beta version, I find the editor more than usable. Sublime Text 2 is a great editor and a lot of Atom is modeled after it (just as Sublime is modeled after TextMate). However, I believe Atom is here to stay and is my main editor for the foreseeable future.