Reader Question: Are there affordable animation programs for the Mac?

Gerard asks:

Hi, I have a MacBook. I want to try out animation, but every time I look for cheap animation programs or free trials, they're all PC. Do you know if there are affordable animation programs for the Mac? I don't want to buy Flash or anything like that. It costs too much.

This is an easy one, as I've gotten this question before. As a matter of fact, there's a list of them posted right here.