[forgotmypw17]

Ruby is great, and I know people who swear by it, but I've yet to come across a GNU/Linux distro which didn't come with Perl installed, while Ruby is not a given in the default, e.g. my current Manjaro.

The compatibility really does stretch back all the way to '94.

[pseudostem]

On OpenBSD, some of the scripts or utils (mandoc) are written in Perl because the developers prefer it. There have been some email chains on the mailing lists about having Perl in base. Most of them are interesting to read.

[anthk]

The pkg_* suite it's written in Perl.