There is a punny word for a smooth experience and, when it comes to Intel "Cilk Plus" integration into GCC, ironically unfit. Version 4.8 was finalized by its committee without Intel's library… and a response to their emails. Once the deadline passed, the next earliest inclusion was at some point in 2014.
Fast forward to now: the library has been approved for inclusion to the project.
According to Phoronix, Cilk Plus extends C and C++ with features for programming in multiple threads (and multiple cores). There are two main advantages: solving for-loops in multiple threads and calling functions as a separate thread. Intel claims the for-loop unrolling feature is not a naive implementation; it will schedule your loop's inner tasks using a divide-and-conquer method to reduce overhead in assigning what does what.
We must still wait until 2014 for its inclusion, however. GCC 4.9, the release which is expected to include Cilk Plus, should arrive at some point within the first half of that year.