This comes off sounding needlessly aggressive, but I'll answer anyway. I was trying to pick up Scheme, and I was using PLT Scheme (now Racket). I would ask on

This comes off sounding needlessly aggressive, but I'll answer anyway. I was trying to pick up Scheme, and I was using PLT Scheme (now Racket). I would ask on a Scheme list / IRC channel "how do I $FOO?" Someone would say "here's some code." That code would not work under PLT because the person in question was using a different implementation with slightly different syntax or language features. I would then spend some time figuring out the exact differences -- usually not long, but it was extra friction that made it harder to get over the learning hump.