wiremod/advdupe2

My seamless portals addon for garrys mod

Garry's Mod add-on that allows users to wire up components in order to make more elaborate automatic and user-controlled contraptions.

Starfall, but with active development and more features. Write Garry's mod chips similar to E2, but in lua

Recreation & expansion of NPCs, entities, and weapons from the Half-Life series into Garry's Mod!

Z-City is a GMod addon which modifies character damage and controls. Z-City also comes with its own weapon base and a gamemode

[NeoForge Mod] Building Tools and Aesthetic Technology

Useful tweaks and content for Source Engine Games

An addon for Garry’s Mod that provides a collection of bases to assist in creating different types of addons.

Tool to mod Portal 2's Puzzlemaker