[sureste]

I get this sort of thinking, but it assumes Chrome follows specs 100%. None of the browsers do that unless it is a very old spec with no recent changes.

There's WebKit, Gecko and whatever they're calling the engine that powers Edge. I don't see a reason to test 10+ browsers if most of them are using WebKit.

[lol768]

I think there's EdgeHTML for Edge (fork), Trident for IE. Isn't Chrome using a fork now? (Blink?)

[Fej]

Chrome and Opera use Blink, a fork of WebKit, which is itself a fork of KHTML.