EtherCalc is a web spreadsheet. Your data is saved on the web, and people can edit the same document at the same time. Everybody's changes are instantly reflected on all screens.
A real time collaborative drawing tool using nodejs, socket.io & paper.js
Etherpad is a highly customizable online editor that allows collaborative editing in real-time.
A safe home for all your data. Access, share and protect your files, calendars, contacts, communication & more at home and in your enterprise.
Redmine is a web-based, flexible and extensible project management and bug-tracking tool.