Valve Source SDK is a software development kit or SDK software, which is created by Valve Software, that is designed to create mods and maps for Source engine, except for some game applications like Portal 2, Left Dead, and Alien Swarm, as they have their own SDKs already. Source SDK has four main utilities and these are to create a mod, refresh SDK content, reset and edit game configurations. In creating a mod, it dumps the code of Source engine into a folder and a mod directory is created under the folder called SourceMods. SDK content is refreshed by checking new data updates as well as downloads. Game configurations can be reset and edited too. Basic games are the basis of how game configurations are recreated, while mods in configurations are removed except if they are edited manually. There are also applications integrated in this kit software, which are Face Poser, Valve Hammer Editor or Hammer and Model Viewer.