Jailing FreeBSD 4 on FreeBSD 10

We have an in-house application that was written for FreeBSD 4 and antediluvian versions of PHP, Perl, OpenSSL, and so forth. Most of the features have migrated into other applications, but a few critical functions remain.

An old operating system isn’t sufficiently bad, though. The hardware terrifies me. Not only is it over a decade old, it’s repurposed desktop hardware.

Virtualize it? Maybe. But device drivers have changed over the intervening decade, and a ten-year-old de(4) or fxp(4) driver...