3 recommended

2
Quip

Beautiful documents on any device.

о.Creative at DMNSNS · Written
You should try Quip. It is not exactly a 'text editor' but even more. It's really hard to explain - just take a look.
CommentsTweet
2
LibreOffice

Andrew WWeb developer · Written
Attractive open source office suite that will feel familiar to MS Office users. A web-based version is also included in OwnCloud.
CommentsTweet
2
Google Docs

Google Docs aren't rich in formatting options, but the collaboration features are still top notch.
CommentsTweet