The Source engine is a 3D game engine developed by Valve Corporation. Its unique features include a large degree of modularity and flexibility, an artist-driven, shader-based renderer, accurate lip sync and facial expression technology, and a powerful, efficient and completely network-enabled physics system.
This Noesis Interactive Database goes with the "Introduction to Dynamite Prop Modeling with the XSI 6 MOD Tool" video tutorial. It contains the scene files and textures used in the tutorial.