Hello everyones ! I was playing with some test frameworks recently and came across what looks like a pseudo-fork bomb. After digging things a little, it seems I am messing with the System.Process.createProcess function : none of my spawned process terminates and eventually my OS freezes. (trivia: well now, I know that Fedora cannot handle more than 1100 processes on my cheap laptop ^^) I've attached a small haskell file which can easily reproduces my problem. If you, carefully, run it from the GHCi prompt while monitoring your pool of processes, you will probably see a hundred of zombie processes appearing. Has anyone got some clues on what's wrong with my function ? Is it related to some strange lazy behavior or should I simply manage each spawned process myself and terminate it when needed ? regards, /John P.S.: speaking of test frameworks, I am desperate to find good examples or documentations on how to use QuickCheck2. Where could I get such resources ?