I assume programming languages lol

HTML and CSS obviously, powered by PHP and SQL, but you wouldn't really touch either yourself on MediaWiki unless you were making an extension. You do work on some PHP but just enough to enable an extension you installed or create namespaces with their own library.

Lua for modules, which integrate with templates. And then in those templates (or just any page) you have some limited HTML, like you can't use but you can use wikicode which does links with a [[ ]] notation, wikicode being another language.

You can write JS and CSS anywhere and we've found out it will actually apply. So it's possible to create a template that does nothing but call a CSS sheet (or js), then invoke that template on a page, and then it will apply on that page only. Pretty cool. We're thinking of making a dynamic search field for the library.

The cards are made with templates which are specific to mediawiki and work like a function that you can call and pass arguments to (which they call parameters), and templates can use Lua modules for more robust functionalities. Like the X number of works mention on the big cards is automatically pulled with a Lua module.

Pretty user-friendly stuff but sometimes you get weird glitches like the grid only using every other column and so you have to find workarounds that would be pretty straightforward on a custom website.