This is a list of external modding related sites that do not quite fit into any specific category.
- Official Source SDK Forums and the now-defunct VERC Network Forums
- Game Design Theory - Interesting for art directors, team leaders
- Gamedesign.net - Some helpful modding and mapping tutorials (broken site)
- GamesModding.com Tutorial Database (Down) archived version - A list of almost every Half-Life 2 modding tutorial out there.
- HL2World.com - Half Life 2 Knowledge Base
- Interlopers.net - News and general resources
- Mapcore - A great place to get mapping, modeling and texture help from industry pros.
- Mod Database - Free listings of mods for almost every moddable game. A great database full of tons of information on mods that are out there.
- Nem's Tools - Several useful Source tools including GCFScape
- SourceWiki Forums - (Main site now closed)
- The RaZZeR App Tutorials/Tools about Source engine development.
- Type 3 Studios - Mods, Maps, Tutorials, Forums, and a thorough community site on the way.
- Wavelength - One of the original sources of HL1 editing material, now steadily servicing HL2
- Wunderboy.org - Several useful Source tools including VTFTool
- ZeqMacaw's Tidbits - Contains tutorials about more advanced stuff for L4D2
- sourcemodding - An Attempt to preserve the modding legacy of Goldsrc, Source and Source 2.