Jira may be extremely sluggish and require a large amount of memory on the client side.
Firepad - Open source collaborative code and text editing that relies on Firebase for real-time data...
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
CryptPad - CryptPad is a collaborative office suite that is end-to-end encrypted and open-source.
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
eduPad - Real-time collaborative text-editor. No account required. Edits highlighted in authors color.
Wrike - Wrike is a flexible, scalable, and easy-to-use collaborative work management software that helps high-performance teams organize and accomplish their work. Try it now.