ChessDB is a free open-source chess database for Windows, Linux, Mac OSX and most UNIX and UNIX-like operating systems. ChessDB is based on code from Scid http://scid.sourceforge.net/ - a project for which there have been no updates for several years. In
Coccinella is a free and open-source cross-platform communication tool with a built-in whiteboard for improved collaboration with other people.
ChemVisio is software which might be useful for educational purposes (non-organic chemistry, crystallography etc.). It might be a good visualization support for all people who need better illustrations than that you could see in books.
Project KVoIP is intended for the account of IP telephony calls. The project is written on Java and will consist of three parts: an application server, a radius-server and a client part.