Welcome

Who are RISC OS Open Limited?

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 the ARM architecture and RISC OS. You can find out more information about us here.

What is RISC OS?

RISC OS is a computer operating system designed in Cambridge, England by Acorn. First released in 1987, its origins can be traced back to the original team that developed the ARM microprocessor. RISC OS is owned by Castle Technology Ltd. You can find out more at sites such as RISC OS Blog, riscos.info, The Icon Bar and RISCOSitory.

If you are new to RISC OS, you might want to look at the introductory pages in our wiki here.

Latest news: Headlines

• Wakefield 2017 (21-Apr-2017)
• Where to store all those noughts and ones (21-Apr-2017)
• Greatest hits album RC15 out now (21-Apr-2017)
• By jove, E’DID it! Monitor setup without the setting up bit (14-Mar-2017)

Recent changes in CVS

• ROOL CVS: Debugger symmetry, assembler fixes, and add AArch32 ARMv8 instructions (21-Jul-2017)
• ROOL CVS: Avoid unpredictable behaviour on old ARMs (21-Jul-2017)
• ROOL CVS: Add AR8035 type in file .. (file was omitted) (18-Jul-2017)
• ROOL CVS: 68 changed components (18-Jul-2017)