Wasn't sure where to put this since I'm not actually interested in development or programming PowderToy. Anyways, my question is in the title. Whenever I play, it sometimes seems to create new .ppm files, however when I download PT as a whole, they aren't there, so I'm just curious about that since I deleted them off of my directory. Which might have been a bad idea since the framerate is now 'capped' around 20 rather than the 60 which seems to be the normal maximum.
Edit: Uninstalling and reinstalling (more like deleting the folder and re-extracting from the download) PowderToy seems to have done the trick of fixing that framerate wierdness.
The .ppm files are screenshot files. They get created when you press p. Not many people know them because nobody can use them. Yes I agree with you that the file format of '.ppm' should be changed to png or jpeg.