One of the most used features on all IDEs is autocomplete. VS has it, Sublime has it, and game engines like Unity or Unreal come with it. Not blender. Until now!
This is Atom.io running on Windows 7, with the autocomplete-python extension configured as such:
Python Executable Paths: …\Blender\2.78\python\bin\python.exe
Extra Paths for packges: api
(Autocomplete-Plus) Keymap for confirming a suggestion: tab always
I plan to bundle this editor with UPBGE and Community Addon, and distribute it all together so that we can get a modern game engine experience with blender.
For it to work, you need the this API folder (containg all the fake Python definitions): https://www.dropbox.com/s/6tijbq5ty14m04n/UPBGECore_API.zip?dl=1
It is not limited to Atom however, any text editor you have that supports autocomplete for Python is most likely capable of using the API files to integrate the BGE API with it.
Notice that, for now, this fake API has been made manually, but I will probably develop a parser for some of the outputs of sphinx (the blender automatic documentation generator tool) that builds the fake API.
EDIT: Now a ready-to-use build can be found here https://blenderartists.org/forum/showthread.php?414991-Bundle-(UPBGE-Atom-io-Autocomplete-CommunityAddon)