Castle Technology - Owners of RISC OS, the RISC OS source code (managed by RISC OS Open Ltd) and also used to make the RISC OS 5 Iyonix computer.
RISC OS Open - Responsible for managing the source code of RISC OS 5, which is free for personal use. Recently, with the help of people from the RISC OS community, RISC OS 5 has been ported to the 'Beagleboard' - an ARM processor powered motherboard with desktop computer capabilities. This is a promising project, which will ensure that RISC OS will appear on newer hardware, especially since the discontinuation of the Castle Iyonix computer in September 2008.
RISCOS Ltd - Develop a variant of RISC OS, known as RISC OS 6 (previously RISC OS 4) for third party hardware such as Advantage 6's A9home computer and the Virtual Acorn RiscPC emulator for Windows. as well as for legacy machines such as the Acorn RiscPC and A7000.
ARMini - The latest ARM powered RISC OS computer, running RISC OS Open Ltd's RISC OS 5. It has been developed by R-Comp Interactive, in partnership with a group of RISC OS companies and enthusiasts.
A9home - Advantage Six's A9home computer running RISC OS 4.42.
Iyonix - Support for Castle's discontinued Iyonix computer.
RISC OS Software
Netsurf web browser- A highly capable, free modern RISC OS web browser, supporting CSS. Also available for GNU/Linux.
MW Software - Develop the ArtWorks vector draw package as well as the EasiWriter and TechWriter series of word processors originally developed by Icon Technology. Also develop other useful software such as the GutenPrint photo-real printing application.
Sine Nomine Software - Software developer selling the Impact database application amongst other software.
David Pilling - Develops Ovation Pro DTP package for RISC OS and Windows.
RiScript - A professional PDF generation package, similar to Acrobat.
Software & Hardware Vendors
CJE Micros - RISC OS hardware and software vendor, as well as being the exclusive UK vendor for Advantage 6's A9home computer. They also develop PhotoDesk, as well as a library of other software.
R-Comp - RISC OS hardware and software vendor. They have developed the ARMini in in partnership with a group of RISC OS companies and enthusiasts and also develop Messenger Pro and Grapevine as well as a library of other software.
APDL - RISC OS hardware and software vendor, also develop the Schema 2 spreadsheet application and DrawWorks, as well as a library of other software.