Perl is probably my favorite language to work with. Its excellent security track record and its powerful taint mode make it my first choice for any project where I care about security, and I generally care a lot about security.
I have contributed several modules to CPAN, Perl's gigantic open source code archive. My CPAN handle is GIFF, and CPAN projects by GIFF include Mail::Qmail::Queue, a tool for modifying mail as it goes into the queue; Net::FTP::RetrHandle, which lets you read arbitrary portions of a remote FTP file asif it were local (including extracting parts of a remote ZIP file without downloading the whole thing); and the rfid-perl project, which created drivers for various RFID readers.
Sometimes if I have spare time I hang out on PerlMonks, where I have the username sgifford. You can see what sgifford has been up to on PerlMonks if you'd like.