Web Compat in Firefox 57

[Sigil]

Web Compat is a system extension that you can spot under about:debugging

As for the addon itself, let me explain what we plan to do. The description already says "Urgent post-release fixes for web compatibility" and that's pretty accurate. The WebCompat team at Mozilla ensures that the web works in Firefox, basically. Sometimes, we release a change inside Firefox that may break specific websites and we need to do something about this. We use this system extension to ship such fixes whenever needed. If you want to, feel free to read more about our Web Compatibility efforts

So, Web Compat basically is a Code Injector, as it may inject code into Firefox on the fly?


What's your assumptions?

[Gingerbread Man]

Opera used to do this, before they switched to Chrome's engine (they still might, I don't know). Since Chrome is the new Internet Explorer, reaching out to web developers who don't test their site in anything else isn't always enough. These sorts of browser maker-issued fixes are an unfortunate necessity, especially when you don't have a large enough chunk of the market share.