It's perhaps worth pointing out that this software is for detecting the presence of any old face, not for detecting a particular face, such as you or Osama Bin Laden.
The author seems to be equating "puzzle languages" with "languages that are very different from the languages I am comfortable with." In other words, it's a classification which is very relative to the experience of the observer.
The languages he describes as "not" puzzle languages are all spiritual descendants of C and Algol, which is a very familiar idiom to many of us.
I imagine that Forth is far less of a puzzle language for Chuck Moore, it's inventor, and that he might find Ruby a bit of a puzzle.
I too was looking for a simple "about" page. Correct me if I'm wrong, but here's my description:
This is a lisp-like language whose principal purpose is to help the creator of the language thoroughly understand how programming languages (especially lisp-like programming languages) work.
Can't agree with this one enough. Also, it is better to write a lot of small scripts, than to write one big one. They will be easier to debug, and you'll get more done.