Work together on documents with your teammates or classmates. Everything is encrypted when stored. You can even set a password on your document for extra protection.
Etherpad is a highly customizable Open Source online editor providing collaborative editing in really real-time.
JetPad is a web-based collaborative text editor.
KodExplorer is a file manager for web. It is also a web code editor, which allows you to develop websites directly within the web browser.
dokieli is a clientside editor for decentralised article publishing, annotations and social interactions.