ROT13 Implemented multiple ways in 58 languages [www.miranda.org]

Mildly amusing - I love that someone has implemented rot13 in postscript - that way you can make sure you don't see the answer to the joke until you print it out I guess ;)

And for people more interested in speed than security, there is a patch to use rot13 as a cipher for your ssh connections!

I notice there is no SysRPL implementation Russell...