Two Decades of RISC OS Open

RISC OS Open: News | Preserving the legacy, managing the present, and engineering the future of RISC OS for the global community.

Posted by: Steve Revill
Date: Saturday, 20 June 2026, 15:13:00 GMT

"On 20 June 2006, we established RISC OS Open Ltd with a slightly reckless goal: to take a closed, proprietary operating system and open its doors to anyone willing to contribute."

Twenty years later, that vision has largely become a reality. The current state of RISC OS is significantly more robust and healthy than the version we first took over. To celebrate this milestone, we are recounting our journey, highlighting one major achievement for every year of our existence.

We owe a debt of gratitude to every individual who has contributed code, reported bugs, funded bounties, participated in the wiki or forums, tested nightly builds, or simply offered their support from the sidelines.

🗓️ The Twenty-Year Timeline

The Early Years: Breaking Ground

Year 1 (2006-07): We attempted the "unthinkable." A shared source initiative between Castle and ROOL was announced in autumn, and by May of the following year at the Wakefield Show, the first sources were finally public.
Year 2 (2007-08): The community received the OS in batches. This momentum led to a Drobe award for "Best show of initiative."
- A community-driven build of RISC OS 5 was showcased on an IYONIX at the Midlands Show.
- Automatic nightly autobuilds were implemented.
- Jeffrey Lee’s BeagleBoard port (a milestone for affordable hardware) won an Icon Bar award.
- The Bounty Scheme was launched, allowing users to crowdfund specific roadmap features.

Expanding the Horizon

Year 6 (2011-12): In collaboration with Piccolo Systems, an open-source SD and MMC filing system was released. This provided native memory-card support for BeagleBoards and stabilized the OS for future releases.
- RISC OS Pi debuted, bringing the OS to the Raspberry Pi and introducing a new generation to the power of BBC BASIC.
Year 8 (2013-14): The first stable ROM release in years, RISC OS 5.20, arrived, adding support for the A7000 family and the classic Risc PC. We also released Pico, a streamlined version that boots directly to a prompt to celebrate 50 years of BASIC.
Year 9 (2014-15): February saw the arrival of quad-core Raspberry Pi 2 support, followed by RISC OS 5.22, which integrated the OMAP4 (PandaBoard) port.
Year 10 (2015-16): The London Show featured Titanium, a dual-core Cortex-A15 board designed specifically for RISC OS. By June 2016, ROOL hit its first decade of operation.

Refinement and Liberation

Year 11 (2016-17): Thanks to a community bounty, EDID support was added, allowing the OS to automatically detect monitor capabilities instead of relying on manual definition files.
Year 12 (2017-18): A massive 520-page revised BBC BASIC Reference Manual was reprinted. RISC OS 5.24 became stable, officially supporting Titanium and Raspberry Pi, accompanied by a community-sourced User Guide.
Year 13 (2018-19): The ultimate goal of 2006 was realized. After RISC OS Developments acquired Castle, the OS was re-licensed under Apache 2.0. For the first time, it was free to use, modify, and distribute commercially.

The Modern Era

Year 14 (2019-20): Development began on the Raspberry Pi 4 port. ROOL also migrated the entire codebase—including over 106,000 commits—to a public GitLab instance.
```
git clone https://gitlab.com/riscosopen/riscos
```
Year 15 (2020-21): RISC OS 5.28 launched with official Pi 4 support and $\approx 700$ improvements. A dedicated edition for the Pi 400 was released just before Christmas.
Year 16 (2021-22): The community voted in the RISC OS Awards, granting 5.28 the title of Best New Development and the ROOL forums Best Website.

Pushing the Limits

Year 17 (2022-23): The Archimedes BASIC Compiler was updated to utilize the hardware floating point unit (FPU).
- Performance Gain: $\text{Mandelbrot Speed} \approx 35\times \text{ faster than interpreter}$ .
- ~~RISC OS was selected by SpaceX for a Mars mission~~ (an April 1st prank).
- New arrivals included a native Git client, open-source SparkFS, and NVMe storage support.
- RISC OS 5.30 was released, supporting seven different hardware platforms.
Year 19 (2024-25): The transition to Git proved successful, with over 1,000 merge requests accepted since 2019. ROOL announced the Moonshots initiative, a multi-year engineering effort to port RISC OS to 64-bit Arm before 32-bit hardware becomes obsolete.
Year 20 (2025-26): Moonshots gained its first wave of volunteers and sponsors. The OS was updated to utilize the full 8GB RAM of the Raspberry Pi, and Fortran was restored to the toolset after being recovered from an old backup tape.

Summary of Progress

Milestone	Detail	Status
Source Access	Shared source $\rightarrow$ Public GitLab	✅
Licensing	Proprietary $\rightarrow$ Apache 2.0	✅
Hardware	Risc PC $\rightarrow$ Raspberry Pi 4 / Titanium	✅
Architecture	32-bit $\rightarrow$ 64-bit (Moonshots)	⏳

Original Goals Checklist:

Open the source code
Enable community contributions
Support modern hardware
Ensure long-term viability

Looking Ahead

None of this was achieved by ROOL in isolation. RISC OS has evolved from a precarious state in 2006 to a vibrant, living ecosystem. We are thrilled to see what the next twenty years hold, from upcoming stable releases to our "leap" toward 64-bit computing.

— Steve Revill and the RISC OS Open Team

Categories: Miscellaneous, Community | Comments: None

SD card Figure 1: SD card support, a cornerstone of the Pi era.

Store: Visit the ROOL Store for merchandise and Raspberry Pi SD cards. IPR: RISC OS is an Open Source operating system.