Getting a little back to original thread. IK and bones are different. They are often used together, but I've seen other applications that had IK, but not bones. You can even have bones without IK, in which case you have to do all the motion yourself, but the bone still deforms the mesh. I believe trueSpace also had IK before they had bones, it's not unusual. Eric Winemiller Digital Carvers Guild Freeware and commercial 3D extensions http://digitalcarversguild.com

Eric Winemiller
Digital Carvers Guild
Carrara and LightWave plug-ins