Crayon Physics was first. The developer, Petri, is a guy who used to run a blog about make-a-game-a-week, and was experimenting with all sorts of ideas, coming up with great concepts for games every week. On June 1st, 2007 he made Crayon Physics and posted it on his blog here:
http://www.kloonigames.com/blog/games/crayonDue to the great response for his game, he decided to improve it which resulted in Crayon Physics Deluxe a year later. He started selling his game for 10-15 bucks, but I guess sales weren't that good which pushed him into the "pay what you want" offer.
That other game is made with MMF2 and came between Crayon Physics and Crayon Physics Deluxe. I'm guessing it was Crayon Physics that influenced the MMF2 developer to make his game (which is why he's not complaining about any of that himself)
Btw, interestingly, even though CP had great potential, somehow the full game didn't amaze me as much as I expected it to. It was still worth every penny (when it actually had a price) but I enjoyed Armadillo Run infinitely more (another great physics puzzle game. Give it a try..)
