See Source SDK 2013 for more information. This time around, the source code is not made available via an SDK launcher, but is instead hosted on Github. With this change, they updated the source code to the latest version of the Source-1-Engine for the HL2-based engine branch. Source 2013 In 2013, Valve phased out the Source SDK with the release of SteamPipe. It also lacks many of the HL2-compatible code's peripheral tools and cannot access HL2's content.
Alien Swarm is totally free to play and its SDK includes source code, but it's source code is for a top-down shooter. Alien Swarm (via Alien Swarm SDK) The oddball of the bunch. You cannot make a mod for Source 2009 you can make a content-only mod of a 2009 game by following Creating a Mod manually. Source 2009 Outdated - Updated Orange Box mod. Source 2007 Outdated - Original Orange Box mod. Only included for backwards compatibility reasons. Source 2006 Outdated - Original Half-Life 2: Episode One mod. Change the SDK's engine version to the one you want. Engine branchīefore starting a mod you need to choose which version of Source you will use. Note: You will need to restart Steam for a new mod to appear in your library.
