The spine-tk2d runtime provides functionality to load, manipulate and render Spine skeletal animation data using 2D Toolkit for Unity. spine-tk2d is based on spine-csharp and is very similar to spine-unity.

A Spine skeleton is a single GameObject and can be used throughout Unity like any other GameObject. The BoneComponent class allows other GameObjects to follow a bone in a Spine skeleton.

Setup

Download the Spine Runtimes source using git or by downloading it as a zip.
Copy the contents of spine-csharp/src to spine-tk2d/Assets/Spine/spine-csharp.
Open the spine-tk2d/Assets/examples/spineboy/spineboy.unity scene file using Unity 4.2+.
Import 2D Toolkit into the project.

Notes

Atlas images should use premultiplied alpha when using the shaders that come with spine-tk2d.
This slightly outdated spine-tk2d setup video may still be useful.