The Source SDK has been updated with content and tools to create maps, models, and textures for Half-Life 2: Episode Two, Portal, and Team Fortress 2. In addition to support for games in The Orange Box, the Source SDK can continue to be used to create content for other top-selling Source engine-based games, such as Half-Life 2: Episode One and Counter-Strike: Source.
Included in the Source SDK are:
Future Source SDK updates will provide new development tools, as well as source code for creating single and multi-player mods that utilize the latest Source engine features.