There are 2 repositories under garrysmod-module topic.
Retrieves client-sided Lua files from Garry's Mod game servers
A module for Garry's Mod that mitigates exploits on the Source engine.
A repository of common bits for compilation projects based on Garry's Mod.
A compact and Garry's Mod compatible SourceSDK (don't use in other Source engine games).
A module for Garry's Mod that provides interfaces to many systems of VALVe's engine, based on gm_sourcenet3.
A module for Garry's Mod that adds hooks for obtaining errors that happen on the client and server (if activated on server, it also pushes errors from clients).
Modules for Garry's Mod that add bindings for OS sockets through luasocket.
Modules for Garry's Mod that add threads through Lua Lanes.
Internal binary module for the luapack project.
Tiny tool for making accessing Source Engine's interfaces simpler
A module for Garry's Mod that interfaces to interact with concommands from VALVe's engine.
Integrate moonscript into your Garry's Mod!
Modules for Garry's Mod for obtaining pointers to functions inside of modules (specially useful for loading Lua only modules).
A module for Garry's Mod that provides interfaces to interact with stringtables from VALVe's engine.
A Garry's Mod module that provides an interface for external consoles.
A Garry's Mod module that copies the log messages and passes them to Lua. Also able to manipulate logging channels.
A Garry's Mod module to create asynchronous child processes. It also allows you to use its error, input and output handles to retrieve or push data to the process.
Make your Garry's Mod I/O asynchronous!
My own collection of random symbols for sigscan with garrysmod_common
Garry's Mod native modules template (not ready, requires changes to garrysmod_common repository)
A module for Garry's Mod that provides interfaces to interact with achievements from VALVe's engine.
real-time MIDI for Garry's Mod
This module extends Garry's Mod's Lua API by providing access to the Source engine's VIS-related functions, which are absent in the native API. It includes a user-friendly interface for PVS byte buffers, enabling efficient visibility checks and data manipulation within Lua scripts.