22 Jun
2026
22 Jun
'26
1:22 p.m.
On 6/20/2026, ben <bfranchuk(a)jetnet.ab.ca> 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+/
SPIN, an extensible operating system written at the University of
Washington, was written in Modula-3 (with small extensions). History and
documentation for Modula-3 are available here:
https://softwarepreservation.computerhistory.org/modula3/ and
information on SPIN is available here:
https://softwarepreservation.computerhistory.org/modula3/#SPIN_M3 .
22 Jun
22 Jun
1:34 p.m.
New subject: What constitutes a dead computer language
On Jun 22, 2026, at 4:22 PM, Paul McJones via cctalk
<cctalk(a)classiccmp.org> wrote:
On 6/20/2026, ben <bfranchuk(a)jetnet.ab.ca> wrote:
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
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+/ 
1:47 p.m.
New subject: What constitutes a dead computer language
On Mon, 2026-06-22 at 16:34 -0400, Paul Koning via cctalk wrote:
Modula-2 was the germ for a lot of good ideas, some of which Wirth
backtracked on with Oberon. The best example is Ada, which has Wirth's
fingerprints all over it, even though he was not an official part of
any of its requirements development or detailed design. The main
failure of Modula-2 was not standardizing I/O, which COBOL, Fortran,
Pascal, and Ada all did. I wrote a lot of Modula code, but it wasn't
transportable because I had to re-write the I/O for every different
compiler + runtime library. I eventually wrote my own I/O layer so that
I could cope with incompatibilities in one place instead of everywhere.
Same as Dave Parnas's 1972 idea for modular programming (but Geschke
and Mitchell had a better idea in MESA — uniform syntax — which Douglas
Ross had earlier described).
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.
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Paul Koning -
Paul McJones -
Van Snyder