LinuxGSM

Complete Open Source and Modular solution for MMO

Open-source engine for Heroes of Might and Magic III

Scalable game server framework with clustering support and client libraries for iOS, Android, Unity and others through the C SDK.

An open source re-implementation of Chris Sawyer's Locomotion

Multi Theft Auto is a game engine that turns Grand Theft Auto: San Andreas into networked multiplayer.

A free and open-source MMORPG server emulator written in C++