The projected texture fixes within the "ASW_PROJECTED_TEXTURES" preprocessor and most of the shader changes involving projected textures are cumulative changes from Insolence's repository using fixes from Alien Swarm, G-String, and City 17: Episode One. (https://github.com/95Navigator/insolence-2013, https://github.com/Biohazard90/g-string_2013, https://github.com/KyleGospo/City-17-Episode-One-Source)
The original code for phong reflections on LightmappedGeneric-derived shaders are from City 17: Episode One. (https://github.com/KyleGospo/City-17-Episode-One-Source)
The Alien Swarm-based radial fog and rope code as well as the multiple skybox support are from Half-Life 2: Downfall. (https://github.com/DownFall-Team/DownFall)
The dynamic RTT shadow angles code is from Saul Rennison on the VDC. (https://developer.valvesoftware.com/wiki/Dynamic_RTT_shadow_angles_in_Source_2007)
Various other code and contributions were based off of pull requests in the Source 2013 SDK (https://github.com/ValveSoftware/source-sdk-2013/pulls) and snippets on the Valve Developer Community (http://developer.valvesoftware.com/).
All of the work mentioned above was open source when it was borrowed.