> On Jun 22, 2026, at 4:22 PM, Paul McJones via cctalk <[email protected]>
> wrote:
>
> On 6/20/2026, ben <[email protected]> wrote:
>> PL/1 and C are the only two high level languages a operating system is
>> written in, that I can think of that are well documented, and easily
>> found on the WEB.
>
> Additional examples:
>
> Pilot (the embedded operating system for the Xerox Star office automation
> system) was written in Xerox's proprietary Mesa language. History and
> documentation of Mesa (and some Pilot documentation and early source code)
> are available here: https://softwarepreservation.computerhistory.org/mesa/
>
> Taos, the operating system for the DEC Systems Research Center Firefly
> multiprocessor workstation, was written in Modula-2+, which added threads,
> garbage collection, and runtime type dispatch to Modula-2. History and
> documentation of Modula-2+ (and Taos) are available here:
> https://softwarepreservation.computerhistory.org/modula2+/
Modula-2-pllus also spread from SRC into the DECnet architecture group, where
we adopted it as the language for writing the pseudocode for the algoritms in
all the Phase V specs.
paul
