As most of you may already be aware that only the native A8 format supports animated models. Unfortunately, exporting animated models in other model formats requires the use on an external 3rd party modeling tool to animate non native formats like 3DS, X, VRML and all of the other exporter based model formats. I use Caligari Truespace version 7.61 Beta 8; also a free modeling software, to export static non animated X, 3DS or VRML models in to TS for the purpose of animating the geometry portion with the key frame editor in TS.
It's quite simple and works somewhat the same as the Anim8or version. TS, uses what it calls the scene editor to display all of the models parts in a separate window that can be expanded to display the time line panel where key frames and the actual frames are shown. Like Anim8or TS also uses inverse kinetics to fill in the in between movements.
Other modeling software like Blender can also be used in the same way to animate your models and further prepare them for final processing.