ONLYOFFICE is a free open source software that helps to organize teamwork online.
ONLYOFFICE Community Server v.8.1 comprises the following features:
- Project management (including Gantt Chart)
- Document management
- CRM system
- Set of tools for collaboration within a team (forums, blogs etc.)
- Email aggregator
- Chat
For more information please,visit
https://www.onlyoffice.com/open-source.aspx