W3Schools has an HTML5 Tutorial. The first example is a video of a bear using the new HTML5 <video> tag. My objective was to figure out how to create the same structure using WebSharper. I was able to create the structure two different ways in VideoBear.fs.
1) Created the structure using HTML, and the output is video_bear_html.html. You can output HTML by creating WebSharper Sitelets. HTML combinators for Sitelets are available from the Intellifactory.Html namespace.
2) Created the structure using JavaScript and the output is video_bear_js.html. You can output JavaScript by creating WebSharper Pagelets. HTML combinators for Pagelets are available from the IntelliFactory.WebSharper.Html namespace. In order to put the JavaScript in an HTML page, you put the Pagelet in a Web.Control that implements INode, and put that in a Sitelet.
Hope that helps. You can browse the code, the output, and even check out the solution.