before LLVM-based languages like Julia or Nim could get a foothold.

Nim isn't an LLVM-based language (not 100% sure you were implying that), though nlvm[1] is a thing.

Regardless, Arraymancer[2] is quite a gem in the scientific computing ecosystem (doesn't build on nlvm, i.e. the mainline Nim compiler is sufficient).

[1] https://github.com/arnetheduck/nlvm

[2] https://github.com/mratsim/Arraymancer