mopac
MOPAC (Molecular Orbital PACkage) is a semiempirical quantum chemistry program based on Dewar and Thiel's NDDO approximation.
TLDR
Perform calculations according to an input file (.mop, .dat, and .arc)
$ mopac [path/to/input_file]
Minimal working example with HF that writes to the current directory and streams the output file
$ touch test.out; echo "PM7\n#comment\n\nH 0.95506 0.05781 -0.03133\nF 1.89426 0.05781 -0.03133" > test.mop; mopac test.mop & tail -f test.out
