Neutron Drive supports a huge range of languages. It is designed to be integrated into either Google drive or your own file server.
Ranked in these QuestionsQuestion Ranking
Pro Realtime collaboration
Pro Syntax highlighting (40+ Language Modes)
Pro LaTeX syntax highlighting
Pro Detailed change tracking
You can enable auto save with changes tracking and get minute to minute tracking of changes. But not good for tracking time spent on a projects because every 30 days or 100 changes gets automatically deleted.
Con Does not support Git
Neutron Drive only saves to Gdrive or a private file server, so there is no github integration.