The skeleton extension allows you to create smooth and realistic animations thanks to the skeleton system. So, you can create background elements and characters with nice animations.
A graphical interface allow you to easily edit skeletons. Thanks to a powerful animation system based on key frames, you can animate the skeletons with smooth movements automatically computed by the extension. Several actions and conditions allow you to act on skeletons in the events.
The extension is available in French and English.
As it is a beta version, it is available only on Windows. But, real release versions will be on Linux too.
Official website : http://gdextensions.levasseursoftware.net/page=skeleton&lang=en
Current Version : Beta 6
In the official website, some documentations are available (for the moment, in French, I’ve just started to translate them in english).