I was thinking more of every web app needing one or more "if isIE() {} else {}" blocks somewhere in its codebase. Now we have the wondrous pleasure of doing the same for Apple.
https://developer.mozilla.org/en-US/docs/Web/CSS/WebKit_Exte...
Just this morning, I had to go down the WebKit pseudo-element rabbit hole to fix a layout bug in a very standard date-of-birth field.