[toyg]

> Sniffing User-Agent has been poor practice since 2011

I'm old enough to remember it was much earlier than that. In the early '00s there were already calls to do feature detection; jQuery was released in 2006 and it basically did it for you. In 2015, there is no excuse to do UA sniffing -- if anything, because we now have 20 years of case-history showing people will trivially spoof it.

[decode]

> In 2015, there is no excuse to do UA sniffing

Unfortunately, there are cases where it is still necessary. For example, IE 10 reports that it supports the CSS pointer-events property, but it only works on SVG elements, not HTML elements.

http://caniuse.com/#feat=pointer-events

[err4nt]

When I went professional with my web development (2009) I can remember the in-the-know people were actively advocating for feature detection, but it was still common practice even in 2010 to add IE-specific support using conditional comments to load stylesheets with fixes for a known IE version.

You probably still have nightmares of these: https://msdn.microsoft.com/en-us/library/ms537512(v=vs.85).a...

On the way to 2012 it became clear once Microsoft said they never intended to let IE announce itself as IE in the future that the game was finally over for UA sniffing. The funniest part was I still remember the MS fanboy blog post that was saying how wonderful it would be that future versions of IE would identify itself as not IE, and how this would make the world a better place. :P