Some systems still use MUMPS in the medical field. To the extent that people still develop expert systems, PROLOG is still used in the development of such syst

Some systems still use MUMPS in the medical field. To the extent that people still develop expert systems, PROLOG is still used in the development of such systems (and various AI projects like Watson use PROLOG internally). A lot of places rely heavily on R and/or Julia rather than Python or FORTRAN for mathematical work these days (although I'd consider FORTRAN at least as 'mainstream' as COBOL if not more -- the difference is that COBOL tends to be legacy business code while FORTRAN tends to be legacy academic code in the hard sciences). There used to be FORTH shops run by FORTH fanboys/gurus who did everything in FORTH. Most of them may be gone, but they existed as recently as the late 90s. Of course, within large organizations there are often groups who end up using obscure languages or technologies for very specific things. The people I work with write a lot of awk.