Goldchest is a new game engine inspired by the old Gold Box style games. The goal is to create a game with the same look and feel of the Gold Box games while bringing to it newer graphics, sounds, music, and network play.
Ryzom Core is a toolkit for the development of massively online universes. It was used to make the commercial MMORPG Ryzom. It provides the base technologies and a set of development methodologies for the development of both client and server code.
FireShot is an extremely lightweight 2D game engine aiming to be simple yet versatile. A few features that make it stand apart are an event based system on top of an event based system (SDL), cross-platform support, and complete control of image blitting.