Various LISPs were a major contender in those times, with various companies selling their own flavors. LISP was the major high-level programming language used for writing operating systems - before C, other OSs were basically written in assembler (though there was at least one written in COBOL, BLIS/COBOL, which seems to have been more or less contemporaneous with C's early life).

FORTRAN was always dedicated to scientific computing, I don't believe it was ever used for system software, so it is a bit apples-to-oranges.

> FORTRAN was always dedicated to scientific computing, I don't believe it was ever used for system software, so it is a bit apples-to-oranges.

Early versions of PRIMOS used FORTRAN as a systems programming language, although later versions switched to Prime's proprietary PL/I dialect (PL/P) and Modula 2.

The reason for the somewhat unusual choice of FORTRAN as a systems programming language? Prime's founders were experienced FORTRAN programmers, so it was the natural choice for them, and in 1972 alternatives were far less established (C was only just being invented)

I think PL/I has more of a claim to have been used for writing operating systems before C than Lisp.

I feel like in the history of software, "computational science," while now a niche was then one of the major users or computers in the early days in addition to business and then eventually, computer scientists. That way we (I am a computational physicist) were one of the major users of large computer systems as they replaced computers, that is, actual people who sat in a room manually computing things. It was only natural then in a certain sense one of the first high-level programming languages were suited for scientific applications like calculation and simulation.

I think since f90, modern fortran still is a language well suited to that domain while removing a lot of the cruft (like requiring each line fit on a punch card, things like that, ugh), although the landscape of computing has changed dramatically since with scientists now being relegated to being a niche of computing as a whole. So fortran in that sense is more like a DSL today rather than one of the major use cases for computers, but by luck and history has a lineage with literally the oldest high level language. This is thus more like a historical accident than being something contingent for me. I think the fact that it is suited to computational science is a result, not a cause of it being for scientists (it was designed for us, we didn't find it and build it up or something like that), and the strict aliasing, well, I feel like that's just a lucky break that it was and thus easily optimizable...that and cray, HP et al did make supercomputers to run codes that scientists liked, and thus their architecture and optimizations worked well with fortran codes, and thus the development of both are clearly a coupled situation here.

Anyway, when it comes to today, modern fortran is still a strong language for computational science, specifically for numerical things like simulation and numerical solution and things like that, so when I say, "it is a DSL for computational science today," that encapsulates my opinion succinctly without having to go into the ramble about history, although history is mostly why it is the case today.

I wouldn't consider Lisp, Algol-60 and PL/I dialects minor languages.