I highly recommend that you give RISC OS a go on your Raspberry Pi! 
RISC OS Open are very pleased to announce the official release of RISC OS for the Raspberry Pi, “RISC OS Pi”. This is a watershed moment for RISC OS and represents the culmination of many months of hard work from a whole community of developers, testers and other contributors. It also means the Raspberry Pi can now boast support for the quick, compact, original ARM-based operating system.
This is the first ‘official’ release of RISC OS for the Raspberry Pi. It is intended to be programmed onto an SD card (2GB or larger) and can be downloaded free from the Raspberry Pi download site, as an SD card image or as a torrent. Alternatively, you can buy a specially-branded SD card already programmed and tested direct from RISC OS Open.
Eben Upton, from the Raspberry Pi Foundation, had the following to say about the RISC OS release: “Having spent a lot of time in my youth pining over Acorn Archimedes and RiscPC products, it’s a great moment for me personally to see an evolved version of the original ARM operating system brought to the Raspberry Pi. From the Foundation’s point of view, we welcome the arrival of an alternative desktop environment, offering a rich suite of applications, and with BBC BASIC only a few keystrokes away.”
Steve Revill, from RISC OS Open, added: “We’re proud and excited to have achieved this milestone in the development of RISC OS. It’s so good to see some great British software engineering to complement the fantastic British Raspberry Pi hardware.”
About the Raspberry Pi:
The Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. We want to see it being used by kids all over the world to learn programming.
About RISC OS:
RISC OS is a fast, light-weight operating system specifically designed for the ARM architecture. It was developed by the same team of engineers who created the original ARM processor and has undergone continual development over the following decades. For the past six years, RISC OS has been opened up into a community project, with its source code published at the RISC OS Open web site. RISC OS is the property of Castle Technology Ltd and can be licensed for commercial use.
About RISC OS Open:
RISC OS Open Limited (ROOL) manages the source code to RISC OS. We are an organisation run on a largely voluntary basis. We also offer professional services to anyone who is interested in developing commercial products using RISC OS.