At Sussex University, the home of Poplog, Adrian Howard maintains a World Wide Web site for information about Poplog and Pop-11. The URLs are, respectively:
http://www.cogs.susx.ac.uk/users/adrianh/poplog.html http://www.cogs.susx.ac.uk/users/adrianh/pop11.html
Ian Rogers maintains a "Frequently Asked Questions" file, at
http://www.cogs.susx.ac.uk/users/ianr/popfaq.txt
This includes some historical notes, with contributions from Robin Popplestone the original inventor of the first of the "Pop" languages (in 1969)
The free (but restricted) Linux version of Poplog, along with other items can be obtained from the Poplog ftp directory at Sussex University. Look in
ftp://ftp.cogs.susx.ac.uk/pub/poplog/poplog15.0 ftp://ftp.cogs.susx.ac.uk/pub/poplog/
The latter directory includes David Young's excellent "popvision" library, with tutorial files and interactive demonstration programs for teaching low level image analysis and interpretation, as well as some very useful image display procedures related to the rc_graphic library.
The "PLUG" (Poplog and pop Languages User Group) ftp site is
ftp://ftp.cogs.susx.ac.uk/pub/plug