The funny characters appear to be ANSI formatting codes (if I set my terminal to something weird, they don't show up), as opposed to what's in the file itself. (I would guess that the C library for dealing with groff/troff/etc. is "groff" itself.) You should be able to find the raw man pages themselves in /usr/(something)/man. The Solaris box I'm looking at now appears to have the man pages in some XML-like language.