Regarding APL\360, I interned at IBM's Cambridge Scientific Center for
a few years before joining DEC in 1980. My first job there was to
write a link editor in S/360 assembler that would run stand-alone on
S/360 hardware (why I was doing this is an interesting story, but long
and way off-topic). This was to replace an existing link editor that
was written in APL\360. It was the largest APL program I've ever
seen--it ran for over 10 pages of solid code! It also ran slower than
death.
-Paul W.