Postgres video blog series by Creston Jamison
Task management/To-do lists
Money, Budgeting and Management
Collaborative software or groupware suites
Web-based project management and bug tracking systems
Self hosted project management, invoicing, and collaboration. Duet provides ever ...
An open, extensible, wiki for your team built using React and Node.js.
Custom communication systems
Zulip is a powerful, open source group chat application.