OT
The new diff script (https://github.com/git/git/blob/master/contrib/diff-highligh...) is juicy indeed.
It is written in Perl. The Perl interpreter is available on most UNIX systems, so that's handy. I wonder if there is any Lisp-like language that is as common, that you can write scripts and expect them to run on most systems. Would be nice since Lisp languages have very few concepts to learn...