WTF, HTML and CSS?
Quick Tip: How to Target IE6, IE7, and IE8 Uniquely with 4 Characters | Nettuts+
A reminder of IE8/IE7/IE6 hacks
Debunking Responsive CSS Performance Myths
On :target
Content Folding
Vendor-prefixed CSS Property Overview « Peter Beverloo
A LESS approach to "Mobile First" CSS & supporting older IE browsers
Internet Explorer 10 Developer Guide:CSS
Exciting reference, shame all properties are still vendor prefixed. "Internet Explorer 10 Developer Guide:CSS"
Responsive Web Design: Helpful Articles, Techniques & Tutorials
Full Browser Width Bars
BoxShadows
Universal Internet Explorer 6 CSS | For A Beautiful Web