Respond.js now available in Modernizr
April 2020 note: Hi! Just a quick note to say that this post is pretty old, and might contain outdated advice or links. We're keeping it online, but recommend that you check newer posts to see if there's a better approach.
Modernizr 2.0 was released earlier this week, with a great new download builder tool that lets you include only the feature tests you need, and nothing more. Yesterday, Scott’s Respond.js script — which brings CSS3 Media Query support to browsers like Internet Explorer 6-8 — was added as an optional include in the Modernizr download builder.
If you’re using both Modernizr and Respond.js already, you may want to consider downloading them through the Modernizr builder, as the file size will be slightly smaller than including them separately.