Sometimes a Linux program requiring fast user interaction/manual dexterity runs too fast for me to keep up. Examples include video games and video players that don't let you control the speed.
How can I slow down the clock for that one process, so that I can interact with the program at a slower rate?
This question is the same as How can I slow down the framerate of a Flash game?, except that that question's answer is a Windows-only program to do this. I'm therefore asking a related question for Linux.