While it's nice to have a book which explains stuff like STL, I've often looked for a good online STL reference where I could get a list of every function in some class, class hierarchies, etc...

It would be nice to have a Javadoc/Doxygen-ish interface with at least a one line description of all functions in STL.

Anyone know of such a page?

And better alternatives exist - like qmail and djbdns. Is there any reason to run those pieces of shit besides legacy config files?

To quote the Makefile for /usr/ports/mail/qmail:

NO_PACKAGE= djb's packaging license does not allow non-standard qmail binary distributions

I would guess this is a big showstopper for using qmail in the FreeBSD basesystem. However, I think it was recently added some glue to sysinstall to let you choose MTA during install.