Perl, also Practical Extraction and Report Language, is an interpreted procedural programming language designed by Larry Wall. Perl borrows features from C, shell scripting (sh), awk, sed, and (to a lesser extent) many other programming languages.
Perl Extensions for FOP
There is a Perl wrapper for FOP designed by Ken Prows called XML::ApacheFOP.
You can find out more about XML::ApacheFOP at: http://search.cpan.org/perldoc?XML::ApacheFOP