I assume you already knew and don't wish to change client -which is fair enough- Weechat supports Python and Ruby in addition to Perl.

I remember the time before Irssi, when even CLI clients regularly had remotely exploitable vulnerabilities in them (including the 1337 BitchX). Irssi was programmed with safety in mind. Either way, scripts increase attack surface.

I'm not using IRC clients right now (I quit after realizing more than 50 windows open isn't productive), but I really love both Irssi and Weechat's interface (including default themes) and CLI. Did have to finegrain the configs but the same's true about nearly any application these days.

Perl is a prerequisite for Autoconf as well (not for the generated configure scripts though, thankfully). It would be nice to not have that dependency.

irssi has support for perl, python, js, tcl and lua(very alpha) https://irssi.org/modules/ None of those other modules are as featureful as the perl module and are looking for people who are interested in developing them further :)