QAvimator is a simple, open source tool for creating and editing avatar animations for Second Life. It started as a Qt port of Vince Invincible’s Avimator. If I’m not wrong, both Avimator and Qavimator are free software; they are available (in alpha stage) for GNU/Linux, Mac Os X and Windows.
I read some documentation and started playing around with Animator. The application seems simple and user-friendly. I chose a photograph of a human pose (thanks, 29man!) and in less than an hour I managed to make this pose. Well, there is a begin.