in reply to
project structure / class browser for Perl?
Personally, I recommend Doxygen.
Doxygen generates JavaDoc-like documentation (all nicely linked) for projects in many languages, including C and C++. DoxygenFilter is a new take on an old project (DoxyFilt) that also handles ("filters") Perl code (including POD), and now promises support for multi-programming-language projects. See Examples of output generated by doxygen.
Another possibility might be NaturalDocs. Ace128 wrote about that here.