Use the [ and ] keys to cycle between distributions.
Press and hold 'a' to lower parameter A, or hold 'Shift' and 'a' to raise parameter A. You can do the same with 'b' and 'c' for distributions that have those. Pressing '9' or '0' changes the random number generator class used here; not all of them work correctly with some distributions! You can see which generator is used (and the current FPS) by pressing ',' (comma).
This uses the font Cozette by slavfox.