Historically, Microsoft’s Internet Explorer has acknowledged web standards with a shrug; even the extent of IE9’s HTML5 support remains in question. If you want to push ahead into HTML5 while continuing to support IE, there are two options: promote an entire engine replacement for IE, or shim it with JavaScript.
ChromeFrame is a plugin from Google for Internet Explorer that replaces IE’s rendering engine, allowing it to understand HTML5, CSS3, while making it faster and more secure. It’s a very good solution, although pragmatically you cannot force users to install a plugin (although you might be able to fool them into doing so).
There are several JavaScript libraries that can be used to make IE play well with HTML5:
Modernizer (now in version 2) has a nice modular approach: like JQueryUI, you can choose what features you would like to have supported. The à la carte menu includes elements from HTML5, CSS3 selectors and properties (including transforms and transitions) and associated technologies such as Geolocation, SVG and WebGL.
Headjs loads scripts and organizes scripts, and updates HTML5 and CSS3 support for IE.HTML5Boilerplate is an "all in one" solution with excellent credentials. It is used as a suite for creating HTML5 pages correctly from scratch, including support for mobile devices and CSS3.

so we don't need the jQuery minimum length anymore:) cool!


