Self-hosted game stream host for Moonlight
Archipelago Multi-Game Randomizer and Server
A free/open source client and automation tool for Ragnarok Online
Open source clone of the Age of Empires II engine
Python MUD/MUX/MUSH/MU* development system
Arianne is an engine to develop multiplayer online games like Stendhal
Stream low latency video from your desktop or webcam over TCP/IP
DOOM / Heretic / Hexen source port with enhanced graphics and UI
Virtual dice working with a server for many users.
The Python/Tk Empire Interface
2D space game with semi-realistic physics
Open Source Virtual World and MMOG Development Platform
Game framework on top of Python, Panda3D and Twisted