A brief survey of various tools with humanoid avatar animation capability
There are a variety of solutions available for producing humanoid animations, both paid and free. We'll accumulate a list here, and hopefully everyone with the knowledge can pitch in with instructions, pointers and tips.
1. QAvimator ()
This older opensource application does one thing and one thing only, and does it fairly well. It allows you to pose an avatar model for keyframes on a timeline, and output the resulting humanoid animation as both a proprietary file and as a mocap motion file (BVH). Version 0.1.1.426 is what has been used successfully with Unity/Space so far.
QAvimator has a fairly intuitive interface developed on Troll-Tech's Qt interface library. It's quite well utilised, resulting in a highly interactive tool with a small executable footprint. Because it was developed on relatively old computers, it isn't very thread heavy and will cheerfully run several copies at once.
The interface loves to get clicked. Click and drag on the background in the scene to move the camera; click on body parts to select them for positioning. Drag the sliders around to change the position and orientation of whatever bodypart is selected.
When you start an animation, never use the first frame. The animator uses that for stuff. Otherwise, clicking to the right of a bodypart listed on the timeline graph will also select that bodypart, at that point on the graph. Any bodypart, once selected, can have it's current position and orientation changed via the sliders.
On the lower right, beneath the sliders, are various parameters pertaining to the actual animation clip, e.g., number of frames and frames per second. Adjust these according to your needs.
There is support for a range of props and prop workflows in this version, but these came a bit after my time and so I will leave it to you all or perhaps another time to describe that set of tools and techniques.
2. Blender ()
4. DAZ Studio