There have been dozens of versions of ecce over the years. I have most recently
made versions for the Macintosh, both as a native application and as an
extension to run within BBEdit (my favourite editor on the Mac).
The version that I run on
Sun Microsystems Inc. SunOS 5.7 Generic October 1998
is based on Pascal source.
You will find the source and manual page in
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce/ecce.pas
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce/ecce.doc
The calling shell-script and SunOS 5.7 binary are in
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce/bin/ecce
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce/bin/ecce1
Source for my Macintosh C/C++ version 3.5 is in
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce.c
Source for my C/C++ Linux version 3.3 is in
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce.cp
There is a general manual page in
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce.txt
There is a (Classic) Macintosh application (Version 2.01) based on Pascal
source in
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/ecce.sea.hqx
There are (Classic) Macintosh BBEdit extensions (including Ecce) in
http://www.cs.ncl.ac.uk/people/harry.whitfield/home.formal/BBXTs.sea.hqx