For all you GTA IV modders out there, that want more then GTA IV can offer due to it’s closed source. There is an excellent alternative in the works called “GRIT Engine”.

GRIT Engine is an open source streaming engine that’s currently in progress for everyone that loves open world environments and GTA style gameplay. It’s build in a way that it’s really easy to create your own maps especially if you’re a GTA Modder. All help is welcome, so if you’re a coder or a modeler and are interested in the project go to the GRIT website and join the forum or IRC.

It’s still a work in progress but it already has a lot of features IV has, including:

  • Code is open source and MIT licensed.
  • Large open world maps, content streamed from disk.
  • Normal / specular / gloss maps
  • Heightmap based texture blending
  • Deferred shading
  • Soft dynamic shadows
  • 24 hour time cycle with sun, moon, clouds
  • Stars at night with real constellations
  • Procedural placement of vegetation and clutter
  • General purpose 3d physics engine.
  • Game objects are extremely scriptable via Lua.
  • We have vehicles (implemented in Lua).
  • Developing/debugging scripts is easy thanks to an in-game Lua console.
  • Linux and Windows ports are available.

Some screenshots of the engine in action:

For more info about this project or try the current version you can go to