The North Korean government has developed its own operating system based on the open source Linux OS.
The "Red Star" operating system has apparently been in development since 2006 but came to light after Russian news channel, Russia Today, covered a blog post by Russian college student "Mikhail".
The student claims that the North Korean OS can be purchased in Pyongyang for $5 and looks very similar to Microsoft Windows, with a similar user interface. The system has both server and client versions, and separate application programmes can be purchased at $10 a pop.
Mikhail also mentions that some North Koreans told him that Red Star is not all that "polished" and that the locals still prefer the Windows treo of XP, Vista and 7.
Installation is pretty reasonable with it apparently taking around 15 minutes, however if you fancy making an order through some North Korean friend, you'll need to be fluent in the lingo since you don't get a choice of system language.