GlTF

glTF (GL Transmission Format; that's confusingly a lowercase l, not an uppercase I, in its mixed-case initialism) is a format for transmitting 3D models and scenes. It has open-source specs that are royalty-free, but claims an unregistered trademark on its name.

Specs

 * glTF 2.0 spec
 * glTF 1.0 spec

Links

 * Official site
 * GitHub site