DC client
Contao Open Source CMS (fka TYPOlight)
CRUD framework with a generic Web UI and integrated micro ORM.
Kurisu OS 3.0
Proofreading Software for 20+ Languages
The leading Open Source survey tool
Notepad++ project is moving to GitHub:
An OpenSource (C# .NET) TeamPlay Environment.
Open Source photo Library Software
Free and open source webmail software
The Koozali SME Server is a simple and robust server gateway for SOHO