IE11 Emulation and Conditional Comments

Conditional comments will work for IE9 and below emulation modes if meta X-UA-Compatible is set to the version that's being emulated.

From Conditional comments do not work when emulating document modes via F12 Developer Tools:

Conditional comments ... are only supported in legacy document modes of Internet Explorer (see http://msdn.microsoft.com/library/ms537512.aspx). In IE11 GA, legacy mode conditional comments are not enabled when choosing a document mode through F12 Developer Tools. Choosing a document mode through X-UA-Compatible, however, does enable conditional comments for the legacy mode.

Test for touch events/device using Javascript

Discussion here:  http://stackoverflow.com/questions/4817029/whats-the-best-way-to-detect-a-touch-screen-device-using-javascript