Bruce66423 points out an analysis at The Guardian of North Korea's Red Star Linux-based OS, based on a presentation Sunday to the Chaos Communication Congress in Berlin : The features of their Fedora based OS include a watermarking system to enable tracking of files — even if unopened. The operating system is not just the pale copy of western ones that many have assumed, said Florian Grunow and Niklaus Schiess of the German IT security company ERNW, who downloaded the software from a website outside North Korea and explored the code in detail. ... This latest version, written around 2013, is based on a version of Linux called Fedora and has eschewed the previous version’s Windows XP feel for Apple’s OS X – perhaps a nod to the country’s leader Kim Jong-un who, like his father, has been photographed near Macs. The OS, unsurprisingly, allowed only tightly fettered access to web sites, using a whitelist approach that gives access to government-controlled or approved sites.