MLDonkey is a multi-protocol, peer-to-peer sharing application that runs as back-end server application. It can be controlled through a web user interface.
Solitaire, also called Patience, is a single-player card games involving a layout of cards with a goal of sorting them in some manner.
Tine 2.0 is an open source business collaboration software covering groupware, CRM and ERP aspects.
Linfo (Linux-Info) is a small and fast GPL-licensed php script that describes the host server.
Geeklog is for managing dynamic web content. Out of the box it is a blog engine, or a CMS and all the vital features of such a system.