Open games by popularity
Many of these games are published under the GNU General Public License (GPL) but also a wide variety of different licenses are used as well, some are more popular than others and some are custom ones. A game can have more then one license, one for the engine and another one for artwork or music.
SLUDGE ("Scripting Language for Unhindered Development of a Gaming Environment") is not only a scripting language for developing adventure games, but also provides graphical tools...
Mangler is an open source VoIP client capable of connecting to Ventrilo 3.x servers. It is capable of performing almost all standard user functionality found in a Windows Ventrilo...
exe2swf is a tool that extracts SWF files from Windows or Mac OS executables., which can then be played on any Flash capable Browser.