Half-Life 2 Garry's mod

Garry's Mod for Half-Life 2 lets you take complete advantage of the physics system by giving you tools to sculpt the world objects as you see fit. Put characters in awkward poses, create your own wheeled vehicles, or even attach objects to flying scanners.

Version 9.0.4 adds a myriad of features and fixes, including new LUA scripts, weapons from Counter-Strike, NPC kill notifications, and improved spawn and weapons menus.