Just a little experiment, best run in turbo mode. I made this so I could compare it to the same script running in Snap! (also make sure to run it in turbo mode there): http://snap.berkeley.edu/snapsource/snap.html#present:Username=jens&ProjectName=Euler%20Spiral Sometimes Scratch 2.0 is frighteningly fast, but in a few cases Snap is even faster :-) [update] OMG, John just showed me this project in the new experimental Scratch player, and there it is sooo blazingly fast that I'm almost ashamed to mention it :-)