[nitrogen]

That page does mention Linux in one section: https://en.wikipedia.org/wiki/Blocks_%28C_language_extension...

[binarycrusader]

That's really annoying; the headline claims one thing and the later text clearly contradicts.

Regardless, both of you appear to be correct:

  BlocksRuntime - a target-independent implementation of
  Apple "Blocks" runtime interfaces.

http://compiler-rt.llvm.org/