Python, Ruby, Haskell - Do they provide true multithreading?

Question

We are planning to write a highly concurrent application in any of the Very-High Level programming languages.

1) Do Python, Ruby, or Haskell support true multithreading?

Answer 1

The GHC compiler will run your program on multiple OS threads (and thus multiple cores) if you compile with the -threaded option and then pass +RTS -N -RTS at runtime, where = the number of OS threads you want.