Topic on Talk:Compatibility

For core, yes. For extensions, it depends.

Are we really supposed to support all versions of Safari since 5.1? It's a bit old.

@Amire80 Is there a specific web platform or browser feature you're finding absent in Safari 5.1? Since 2015, our support matrix is mainly based on feature detection, not browser detection. (See startup.js)

Not really. I was just surprised that we have something pretty old here.

I came here because of a question at Topic:U4chyrpe83knqy0y.

@Amire80 Okay, that makes sense (the topic is about ContentTranslation).

This page is for MediaWiki core, and describes its basic and enhanced features. Other WMF projects, if not otherwise defined, are assumed to follow it, but you don't have to.

Individual features, such as those provided by extensions, may have a different compatibility policy. WikiEditor and VisualEditor both had this for a long time. (Right now they don't because core caught up with them.)

If you have a different policy, make sure that you use a feature test that will gracefully make the code do nothing in older browsers (e.g. an early return and/or some kind of fallback message indicating the issue of browser support).