C, BLISS, BCPL, and the like were hardly the only systems programming languages that targeted the PDP-11.  I knew about many system programming languages of those times and used all three of these, plus a few others, such as PL/360, which Wirth created at Stanford in the late 1960s to develop the Algol-W compiler.  Recently, I was investigating something about early systems programming languages, and a couple of questions came to me that I could use some help finding answers (see below).

In 1971, RD Russell of CERN wrote a child of Wirth's PL/360 called PL-11: Programming Language for the DEC PDP-11 Computer in Fortran IV.  It supposedly ran on CERN's IBM 360 as a cross-compiler and was hosted on DOS-11 and later RSX. [It seems very 'CARD' oriented if you look at the manual - which makes sense, given the time frame].  I had once before heard about it but knew little.  So, I started to dig a little.

If I understand some of the history correctly, PL-11 was created/developed for a real-time test jig that CERN needed.  While it was available in limited cases, since BLISS-11 required a PDP-10 to cross-compile, it was not considered (I've stated earlier that some poor marketing choices at DEC hurt BLISS's ability to spread).  Anyway, a friend at CERN later in the 70s/80s told me they thought that as soon as UNIX made it on the scene there since it was interactive and more accessible, C was quickly preferred as the system programming language of choice. However, a BCPL that had come from somewhere in the UK was also kicking around.

So, some questions WRT PL-11: