What program can print source code well on OS X? I am looking for an OS X application to nicely format and print source code from a variety of programming languages.


Line numbers would be nice
Constant width font
Printing the contents of the clipboard would be a real plus


Does something like this exist (besides the obvious programmers' editors), free or reasonably priced?
You will find a nice answer over at sister site superuser. It involves a terminal program called enscript which comes with lot's of options and I know at least of one support file for extending its capabilities to print Ruby code.

EDIT:

I just noticed the "clipboard" part of the question. The clipboard content can be accessed from the command line and fed to enscript using pbpaste as mentioned in Matteo answer.