Embed a Scratch applet in HTML5

For the past year I've been following the progress of HTML5 with interest. And recently I've become interested in MIT's Scratch. So naturally I've been test embedding Scratch using it's Java applet in HTML5. The only article I've found so far on embedding Scratch in HTML5 contains a number of errors and invalid markup, so I'm setting the record straight.

First, the situation in HTML 4.01/XHTML 1.0 – <object> is the preferred element, with <applet> deprecated. So, <applet> is valid in HTML 4 Loose (XHTML 1.0 Transitional), but not HTML 4 Strict.

Drum Kit 2.0, by technoguy

Example embed for HTML 4.01:

<applet codebase="http://scratch.mit.edu/static/misc/" archive="ScratchApplet.jar"                                                           
        code="ScratchApplet" height="387" width="482">                                                                                                             
   <param name="project" value="../../static/projects/technoguyx/355353.sb" >
   Your browser needs Java to view projects.                                                                                      

Flash wmode considered harmful

Despite the emergence of the <video> element in HTML 5, Shockwave Flash is still the defacto standard for publish multimedia on the Web. Macromedia, and now Adobe have improved the support for assistive technologies and software interfaces like Microsoft Active Accessibility (MSAA) within the Flash browser plug-ins and it is now possible to create a video player in which all the controls and status information are perceivable by screen reader users. So all the challenges to do with Flash have been overcome, no problems? Wrong.

I and others have uncovered what appears to be a little publicised or little known flaw that renders some of the "embed codes" displayed at sites like YouTube, Vimeo et al completely inaccessible.

Screen shot, wmode = window - default, OK