References:
http://www.fevrierdorian.com/blog/post/2012/04/04/Python-multiprocessing-vs-threading
http://bisqwit.iki.fi/story/howto/openmp/
http://www.linux-mag.com/id/1001/
http://www.cs.nmsu.edu/~jcook/Tools/pthreads/pthreads.html
http://openmp.org/wp/openmp-compilers/
http://www.eng.cam.ac.uk/help/tpl/languages/parallelprogramming.html
http://gcc.gnu.org/onlinedocs/libgomp/
http://www.tldp.org/HOWTO/Parallel-Processing-HOWTO.html
http://aggregate.org/PPLINUX/19960315/ppsmp.html
https://computing.llnl.gov/tutorials/pthreads/
http://users.actcom.co.il/~choo/lupg/tutorials/multi-process/multi-process.html