Cockatrice by Max-Wilhelm Bruker is an open-source multiplatform software for playing card games, such as Magic: The Gathering, over a network. It is fully client-server based to prevent any kind of cheating, though it supports single-player games without a network interface as well. Both client and server are written in Qt 4. Cockatrice is fully GPL licensed and thus free software.

Ported to Pandora by Canseco.