Editing PERQ (section)

===Operating systems===
A variety of [[operating system]]s were developed for the PERQ. These included:<ref name="faq"/>

;POS (PERQ Operating System): The initial single-task operating system for PERQ workstations, developed by 3RCC. POS and its utilities were written in PERQ Pascal.

;MPOS (Multitasking POS): A [[Computer multitasking|multitasking]] version of POS, not officially released by 3RCC.

;[[Accent kernel|Accent]]: A multitasking research operating system developed at CMU, with a [[window manager]] called Sapphire. Accent was a predecessor of the [[Mach kernel]] which many later operating systems would use. A [[UNIX System V]]-compatible environment running under Accent in a Sapphire window, called ''QNIX'', was developed by [[Spider Systems]].

;PNX ({{IPAc-en|'|p|i:|n|ɪ|k|s}}  {{respell|PEE|nix}}): A port of [[Unix]] for the PERQ, based on [[Seventh Edition Unix]] and [[UNIX System III]]. This was developed by ICL at [[Bracknell]], [[Dalkeith Palace]] and later [[Kidsgrove|Kidsgrove (Staffordshire)]] for the UK research community.<ref name="faq"/> PNX used its own microcode, more appropriate for the [[C (programming language)|C programming language]], called ''C-Code''.

;[[Flex machine|FLEX]]:  Developed by the [[Royal Signals and Radar Establishment]], FLEX was implemented in microcode and similar to other early workstation systems such as [[Lisp machine]]s, [[UCSD Pascal]] or [[Modula-2]], except that the language of choice was [[ALGOL 68]].