"Unlike the Steam Workshop or local content mods, this SDK gives mod makers the ability to change, extend or rewrite TF2, making anything from small tweaks to complete conversions possible," Valve ...

Modding tools have been available for these games for a long time, and fan-made content has always been an important part of the Team Fortress community. Custom content is integral to TF2, with a ...

Quilkin is a non-transparent UDP proxy specifically designed for use with large scale multiplayer dedicated game server deployments, to ensure security, access control, telemetry data, metrics and ...

My TF2 HUD and one of many hobby projects. Readme has the info and links you need.