This lets you animate models using the ValveBiped skeleton. It is powered by JetBoom's Lua Animation API.

http://www.facepunch.com/showthread.php?t=821202

Just extract the contents of the zip to garrysmod/lua/

HOW TO USE: Type "animate" in console once it is installed.

When you save animations to a file, that file will be in garrysmod/data/animations/{animname}.txt



Changelog:

1.51
*Fixed issue with certain panels (spawnmenu among other things) blocking the mouse hooks from working correctly

1.5
*Made the changes reflect realtime
*Added 3d drag rotation (drag left and right)
*Fixed various annoyances
*Timelines play over sub animations
*Selecting keyframes now shows you how the animation will look properly blended with all sub animations at the end of that keyframe


1.4
*Added support for people to add their own bone sets if needed
*Added support for ValveBiped (Vortigaunts use this)
*Fixed StartFrame not being dumped to raw lua


1.3
*Fixed timeline bar to work with restart positions
*Added support for StartFrame with sequences

1.2
*Added timeline bar to show progress of a playing animation
*Added ability to see animations blended with other animations



1.1
*Changed camera to move around the player as well as up and down
*Added raw lua dump button
*You can now type values into the Slider boxes