I don't think it's necessarily that difficult to code for multiple cores in appropriate languages. The problem is that it requires a rethinking of what programm

I don't think it's necessarily that difficult to code for multiple cores in appropriate languages. The problem is that it requires a rethinking of what programming is and how it's supposed to work. It's difficult to test or examine concurrency interactively. Interactive development and unit testing allow you to answer the question, "does it get the job done, and well?" Before multicore, answering that question was enough. With multicore, the question is, "does it get the job done well, with efficient use of low-level resources, and regardless of the unpredictable interleaving of concurrent instructions?" This is where functional programming comes in, because it makes the leap from answering the first question to the second trivial.