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 specialist professional services to anyone who is interested in developing products around the Arm architecture or 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. You can find out more at sites such as riscos.info, The Icon Bar and RISCOSitory. Also take a look at the printed RISC OS magazine, Archive, first published in the same year as the Arm launch, or the digital publication Drag N Drop for in-depth reviews and articles.

If you are new to RISC OS you might want to look at the introductory pages in our wiki, or come along to one of the shows and user groups.

Latest news

• Two Samba, or not two Samba? SMB2 lands in the nightly builds (22-Oct-2026)
• Laser focused on London (15-Oct-2026)
• Match finished: a look at the final scores (28-Jun-2026)
• Twenty years of RISC OS Open (20-Jun-2026)

Recent changes in GitLab

We’re upgrading our GitLab instance and the Recent Changes feed will be offline for a while.