RISC OS, the operating system with its roots in Acorn's 1987 Archimedes micro and therefore the birth of the ARM processor architecture, has been released for the Raspberry Pi.
Available as a free download, or pre-loaded onto an SD card for £10 plus postage, the release for the Pi is version 5.19 RC6. There's also a £35 software bundle on offer, dubbed NutPi, that includes all manner of useful applications to turn a RISC OS Pi into a viable everyday machine.
The OS will confront users with the need to learn some technical skills almost as soon as it is booted, as the Pi's ethernet port is switched off by default in order to speed boot times.
A tutorial available as part of the default install explains how to enable networking.
If that's not enough for you, the OS also includes BBC BASIC, giving your hippocampus the chance to dredge up some very old syntax from deep memory.
The RISC OS version offered is release 5.19 RC6 and has already had a few changes made, detailed here, since a late October pre-release. ®