Editing RISC OS (section)

== History ==
{{Main|History of RISC OS}}
[[File:Riscos logo generic cogwheel richard hallas lg cogwheel x1.svg|thumb|110x110px|Original cogwheel logo]]
The first version of RISC OS was originally released in 1987 as ''Arthur 1.20''. The next version, {{nowrap|Arthur 2}}, became {{nowrap|RISC OS 2}} and was released in April 1989. RISC OS 3.00 was released with the A5000 in 1991, and contained many new features. By 1996, RISC OS had been shipped on over 500,000 systems.<ref>{{cite web|url=http://acorn.chriswhy.co.uk/docs/Acorn/ART/ART_DS013_AcornRISCOS.pdf|title=ART – Acorn RISC OS|work=acorn.chriswhy.co.uk|access-date=8 July 2011|archive-date=27 May 2013|archive-url=https://web.archive.org/web/20130527220851/http://acorn.chriswhy.co.uk/docs/Acorn/ART/ART_DS013_AcornRISCOS.pdf|url-status=live}}</ref>
[[File:Acorn Archimedes A3020 ( Bletchley Park, translucent ).png|thumb|An Acorn Archimedes A3020 computer running RISC OS]]
Acorn officially halted work on the OS in January 1999, renaming themselves [[Element 14 (company)|Element 14]]. In March 1999 a new company, [[RISCOS Ltd]], licensed the rights to develop a desktop version of RISC OS from Element 14, and continued the development of RISC OS 3.8, releasing it as ''RISC OS 4'' in July 1999. Meanwhile, Element 14 had also kept a copy of RISC OS 3.8 in house, which they developed into [[NCOS]] for use in [[set-top box]]es. In 2000, as part of the acquisition of Acorn Group plc by MSDW Investment, RISC OS was sold to [[Pace plc|Pace Micro Technology]],<ref name="register19990429">{{ cite news | url=https://www.theregister.com/1999/04/29/arm_denies_role_in_acorn/ | title=ARM denies role in Acorn dismemberment | work=[[The Register]] | date=24 April 1999 | access-date=31 January 2021 | last1=Cullen | first1=Drew }}</ref> who later sold it to [[Castle Technology]] Ltd.

In May 2001, RISCOS Ltd launched ''RISC OS Select'', a subscription scheme allowing users access to the latest RISC OS 4 updates. These upgrades are released as soft-loadable [[ROM image]]s, separate to the ROM where the boot OS is stored, and are loaded at boot time. Select 1 was shipped in May 2002, with Select 2 following in November 2002 and the final release of Select 3 in June 2004. In the same month, RISC OS 4.39, dubbed ''RISC OS Adjust'', was released. RISC OS Adjust was a culmination of all the Select Scheme updates to date, released as a physical set of replaceable ROMs for the RiscPC and A7000 series of machines.

Meanwhile, in October 2002, [[Castle Technology]] released the ''Acorn clone'' [[Iyonix PC]]. This ran a [[32-bit computing|32-bit]] (in contrast to [[26-bit computing|26-bit]]) variant of RISC OS, named ''RISC OS 5''. RISC OS 5 is a separate evolution of RISC OS based upon the [[NCOS]] work done by Pace. The following year, Castle Technology bought RISC OS from Pace for an undisclosed sum. In October 2006, Castle announced a [[Source-available software|shared source]] license plan, managed by [[RISC OS Open Limited]], for elements of ''RISC OS 5''.

In October 2018, RISC OS 5 was re-licensed under the [[Apache 2.0]] license.<ref>{{Cite news|url=https://www.theregister.com/2018/10/23/risc_os_open_source/|title=Roughly 30 years after its birth at UK's Acorn Computers, RISC OS 5 is going open source|first=Richard|last=Speed|work=[[The Register]]|access-date=26 October 2021|archive-date=23 September 2021|archive-url=https://web.archive.org/web/20210923185001/https://www.theregister.com/2018/10/23/risc_os_open_source/|url-status=live}}</ref>

In 2018 [[RISC OS Developments]] acquired Castle Technology Ltd including its intellectual property.<ref name="riscosdev">{{cite web |url=https://www.riscosdev.com/ |title=Home |website=riscosdev.com}}</ref>

In December 2020, the source code of RISC OS 3.71 was leaked to The Pirate Bay.{{cn|date=May 2022}}
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