Wow, brings back old, old memories of seeing the C/Unix source listings lying on my office mate's desk (Geoff Steckel) at the old Harvard CRCT (graduate Center for Research in Computing Technology). I'm pretty sure Harvard had the first sources released outside of Bell Labs, in '73 or '74.
Since some of the original PDP-11 line printers (LP11's) didn't have lower case, upper case was indicated by struck-through upper case and lower case was plain upper.
I remember, after being steeped in Lisp-family languages (ECL), but also Bliss-11 (from CMU), my curiousity at seeing a "high-level" language that was so close to the machine in a different way than Bliss (which had a lot to recommend it) but also with a completely different approach to data structures. (C grew out of BCPL, while Bliss used what were effectively compile-time procedures to let you arbitrarily define your structure access.)
That includes (free) licenses. If you want to use these compilers to experiment, you can get a VAX emulator here http://simh.trailing-edge.com/ (boots and runs on Linux, Mac, Windows) and a VMS license and media are available for the cost of a CD (US$30).
Since some of the original PDP-11 line printers (LP11's) didn't have lower case, upper case was indicated by struck-through upper case and lower case was plain upper.
I remember, after being steeped in Lisp-family languages (ECL), but also Bliss-11 (from CMU), my curiousity at seeing a "high-level" language that was so close to the machine in a different way than Bliss (which had a lot to recommend it) but also with a completely different approach to data structures. (C grew out of BCPL, while Bliss used what were effectively compile-time procedures to let you arbitrarily define your structure access.)