I don't get the constant complaints about the GIL.  Letting your Python program run on 2 cores will make it 2x faster at best.  Rewriting it in, say, Javascript or Lisp or Haskell or Java will make it run 2-50x faster on one core.  After you get your 50x speedup, then you can worry about the 4x you'll get from buying 3 more processor cores.<p>(And oh yeah; it's only shared-memory concurrency that things like the GIL affects.  If you have a job to do that wants to use 8 cores, split the job up into 8 parts and invoke your program 8 times.  There's your 8x speedup.)