It is fully ethical and acceptable to make millions of $$ with the product without giving the author a penny. He licensed it under MIT , so from the very beginning he is not looking for money for this. If he picked the license by mistake, then he ought to be responsible for the consequences.
mpc made only a couple thousands dollars from this. It’s very little comparing to the potential projects/gigs the author could get if he approached mpc for a link in his website or a small feature. The author is clearly unprofessional, and lacking both in business and diligence.
mpc, I have just purchased the fat HTML5 Canvas book from Oreilly exactly to get in this field of interaction design for the web. I’m looking for awesome ideas to start hacking on and that looks like a good entry project. The script will be MIT licensed (or GPL /MIT); no threats, no noise and no bullshit. Free to use, and no blame if you don’t donate.
You can reach me on Skype (omar-abid) if you have ideas/suggestions or thinking of improvements that can be made to the project.