Support for XHTML in HTML5 is an increasing requirement from many developers. However, W3C does not consider XHTML5 as a dedicated standard even if it's fully valid to serialize HTML5 as XHTML
Yet, there seems to be only pretty few attempts of building a proper XHTML5 validation schema or DTD out on the on the web. Microsoft has made one available, but it's proprietary and works only within VisualStudio. Another one follows with XMLmind XML Editor, but also that one is close sourced (even if it's also based on the library I use)
The only open sourced XHTML5 XSD I could find, was the one written by
Olivier Ishacian. I took this library as the basis for my project and extended it with support for Microdata,
SVG and MathsML.
I have to confess, I'm not an XML guru, so the code will probably need a lot of improvement.
Want to contribute? That would be great! Fork the project on GitHub.