Garry's Mod/en
Garry's Mod is a sandbox game, created by Garry Newman. It is centered around putting the player in an environment, in which they can do nearly anything that the Source engine is capable of. It was heavily inspired by JBMod. Early versions of Garry's Mod, which at the time ran directly on HL2 game files (Source 2006) as opposed to the 
Source SDK Base 2006, modified several normal Half-Life 2 weapons to act as different tools (like the 357 Magnum Revolver being able to set the cameras, for instance).
As time went on Garry's Mod was updated even more to resemble JBMod, now running on the SDK Base engine, and later its own fork of Source 2013. Garry's Mod has advanced through 13 major updates, each with more features than the last. The latest version has a massive host of features, such as easier ragdoll posing, keypads, doors, buttons, dynamite, welding, and just about everything needed to create contraptions as well as comics and videos.
Garry's Mod has a large addon and mod base and supports 
Lua, which is used by the community to make new weapons, entities, and gamemodes. Gamemodes range in genre from the original sandbox, to roleplay, survival, sports and far beyond. The community also considers the game to be by far the most popular Source mod. It was also the first mod ever distributed through Steam.
Garry's mod as a development tool
Garry's Mod is useful for Source developers, and can greatly fulfill certain tasks needed to make new mods or add-ons. Tasks such as:
- A way to place and or move props in MAP_EDIT mode
- A user-friendly demonstration tool
- Chat with other modders and share ideas through text and usage of Gmod tools. Devs can use GMod's tools to cooperatively share ideas about mod scenarios with players. Gmod can also be used to demonstrate a new map and discuss features without NPCs.
- Stress-test Source
- Use Garry's Mod to test abusive usage of the Source engine, like spawning hordes of zombies, spamming explosive barrels and other intensive things. Will it crash? Will it freeze? Will the network buffer overflow?
There is also a beta branch that supports a 64-bit executable (for both the game and the compile tool itself) and Chromium. This will allows Source to better utilizing the hardware's CPU, and allow the game and compile tools to use more than 4GB of RAM.
- Quickly test game elements
- With the implementation of Lua scripting, you can create new game elements and weapons without using the Source SDK and make the process go a lot faster.
Links
- Official website
- Garry’s blog
- Developer's website
Outdated ModDB Page - Free older versions of Garry's Mod (version 9 and below) can be found from there.
Garry's Mod on Steam Store- Garry's Mod on Steam Community
Garry's Mod on Wikipedia- Getting started in the Hammer editor for Gmod!
- List of Garry's Mod Cvars
