Keep your CSS selectors short — CSS Wizardry—CSS, Web Standards, Typography, and Grids by Harry Roberts
"One thing I believe, as a very, very general rule of thumb, is that as sites get bigger, selectors should get shorter."
"The @-ms-viewport rule is based on the @viewport rule, which is defined in the CSS Device Adaptation specification."
CSS WG Blog – How to unprefix -webkit-device-pixel-ratio
"So to unprefix -webkit-device-pixel-ratio all you have to do is convert it to resolution—which is already implemented by all the other browsers. The easiest way is to multiply the value by 96 and append dpi."
12 CSS3 Vendor Prefix Crisis Myths - SitePoint
"The issues are widely misunderstood — which is why we find ourselves in this mess. Hopefully, this article will shatter several vendor prefix crisis myths…"
Mac App Store - Aptus
"Aptus is a dedicated browser that lets you preview, edit and screenshot your responsive site at any size from mobile through to large desktop."
Nu Markup Validation Service Bookmarklets | The Paciello Group Blog
"I noticed that the W3C Nu Markup Validation Service did not have any bookmarklets to provide quick validation of a page currently being viewed. So I made some using the existing W3C validator bookmarklets as the basis"