Are you really sure you don’t care about the speed? 
I remember (I tried it several years ago) that CPU based execution was several orders of magnitude slower than GPU based. In other words, instead of fluent animation you cannot get even a slide-show.
If the program requires GL 2.1, it probably have a good reason for that. So, don’t try to fool it. For example, it might require PBO or non-quadratic matrices that are not supported in GL 2.0.