Python, Perl, PHP, Java, JavaScript… using various libraries developed for use with Twitch Message Interface.
Java - https://github.com/blay09/JavaTMI
JavaScript - https://github.com/Schmoopiie/tmi.js/
Python - https://libraries.io/pypi/spasm
This was just a quick search but there is lots out there.
mIRC is made for IRC and takes a lot of work to get everything “just right”. TMI is based on IRC, but isn’t IRC. Depending on your scripting/programming skill you might be able to make mIRC do everything you want, even the complex things. At that point it’s pretty much about efficiency and speed. Stacking more and more to get it to be where you need it to be to work.
I’m sure more people can elaborate on this and some people will say it works fine…
…and I’m sure it will work fine for some things… lots of things…
It’s just not the best way, not the cleanest way, not the most efficient way.