Very cool feature on Google Chrome; record your actions and playback later for bulletproof demos.
Then http://browserhacks.com is the site for you!
Some good stuff on this article on 20 Snippets You should be using from Html5 Boilerplate.
Nice list on github on the range of meta tags that are possible (along with your own custom ones).
iPhone 5 and iOS 6 for HTML5 developers provides a really good breakdown on the changes and additions available for the new device/OS.
Lots and lots and lots on responsive web design here.
This took me the best part of a bank holiday weekend to download but got there in the end. Useful guide on how to get virtual Internet Explorers running on your Mac for development purposes, although I’ve only 59GB remaining on my rMBP as a result.