A robot in a glTF viewer.

glTF (gl Transmission Format) is a free file format for 3D scenes - and models. Like Collada, it was developed by the Khronos Group (www.khronos.org), a consortium of graphics companies. It is optimized for efficient transmission and loading of 3D content, which makes it ideal for real-time applications on the network (Facebook, for example). Also, many 3D engines like Unity or Unreal can import this format.