If there have already been more than 500,000 RPi's sold, and this trend keeps for a few years, the RPi is well on its way to taking over the title of the single most succeful single computer model system in the world. The Commodore has long held this title with its 12.5Milion, though the Pi is already passing up the sails figures of the C64..
RPi = The best ARM based RISC OS computer around
More than 95% of posts made from RISC OS on RPi 1B/1B+ computers. Most of the rest from RISC OS on RPi 2B/3B/3B+ computers