They also used PRIMOS. I worked in FORTRAN (4), PL/1, and C.
What would be really strange if you worked on GLE a PL1/G program the US side made for our Billing system.
The legacy stuff was FORTRAN. Did I say 4?
My mistake. '77.
A hundred KLoC of spaghetti, just like Mama Mia used to make.
The X.400 stuff was in C, but I'm not sure that the stuff I worked on made it to the customer. We wrote a mover application.
They also used PRIMOS. I worked in FORTRAN (4), PL/1, and C.