Comment by pjmlp

All the safety improvements of 21st century wannabe C replacements, were already available in NEWP(1961), PL/I (1964), Mesa (1976), Modula-2 (1978), PL.8 (1982), Ada (1983), Object Pascal (1986), among many other lesser known ones.

However none of them had an OS available in source code for the symbolic price to send tapes around to universities.

Additionally, the remark that the UNIX and C authors themselves did not stop there, and their latest mark on the computing world was the Go programming language, after Limbo, and the acknowledgement that designing Alef without a GC was a mistake.

Probably they would not had to reboot Plan 9 OS design into C.