Run3 is an open-source game engine built with Ogre and inspired by the Source engine. The project started in 2009 and is licensed under the MIT License.
Run3 exists as a run3_r.exe
executable and related DLLs. There are no dedicated content creation tools; you can work with whichever tools you prefer. Existing utilities include RunEdit (a legacy map editor), RunRepresent (model viewer), FacialAnimation (lip sync), and Run3Mat (a console utility for material batching). Ogitor assists with mapping, CaduneTree for procedural trees, the CEGUI Editor for GUI, and CEGUIMeshViewer for mesh fixing.
For a high‑level overview see docs/index.md. Build instructions are located in docs/BUILDING.md.