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 Source 2009 Outdated - Updated Orange Box mod. Source 2007 Outdated - Original Orange Box mod.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 Source 2006 Outdated - Original Half-Life 2: Episode One mod.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.
