Once you have imported the Space Editor Pack into Unity, you will find a Gesture Preview Scene.
This scene contains two rigged character models and is set up to allow you to assemble and test your gestures.
Only add one gesture into the scene at a time.
The Space virtual world uses the Unity game engine and supports FBX animation files. If you are used to using BVH files there are utilities online that can convert from one format to the other.
For more information on animations and Unity;
http://docs.unity3d.com/Manual/AnimationSection.html
https://unity3d.com/learn/tutorials/topics/animation
When you import an animation into Unity you will then add that animation to a game object (there are templates in the Gestures folder in your project).
That game object has scripts added to it, depending on what you are doing with your gesture.
Those scripts can include;
PENDING
Your gesture will also have a Virtual Goods Script attached, which allows you to add product information and submit the item to the store and / or your inworld inventory.
For more information on the virtual goods script;