Or in geek terms: 1 + i - 1

If you're going to the length of building from source yourself, you might also want to try pkgsrc.org, depending on your needs.

I found NetBSD won't boot either, at least with VirtualBox 2.1. I recall seeing that DragonFly BSD also didn't boot on an older version of VirtualBox without a patch, so it seems it isn't ideal for any of the BSDs right now.

Well, technically it isn't installed by default on FreeBSD or NetBSD (and possibly DragonFly BSD). FreeBSD stopped shipping it in base some six years ago (http://bsd.slashdot.org/article.pl?sid=02/05/14/0015234), and I'm not sure NetBSD ever included it in base. OpenBSD is the only BSD I know of that continues to include it in base; they have to, their package install system depends on it. (On the other hand, in SVR4-land, HP-UX started including Perl by default in 2001, it seems.)