Of course, the first thing I've checked after setting this blog is whether it is possible to have a XHTML+MathML+SVG page in dotclear. As indicated in the Mozilla MathML Project page, one has to:

1. serve the page as application/xhtml+xml.

This is simply done by editing the value of parameter \$content_type in the function serveDocument of the file dotclear/inc/public/lib.urlhandlers.php.

2. write well-formed XML document.

Apparently, dotclear is good enough to do that. However, its editor does not seem to have any option for producing MathML or SVG. Personally, I don't use the wiki syntax and prefer to write the XHTML page myself with the tools I'm used to. As a consequence, this is not really a problem for me.

It is also a good idea to write a valid XML document. By default, dotclear uses the doctype XHTML 1.0 Strict so I had to modify the files themes/name_of_your_theme/tpl/*.html to set XHTML+MathML+SVG instead.

Once this simple changes are made, you can insert MathML formulas such that this expression of a general Quantum Fourier Transform over a finite group:$\forall g\in G,{F}_{G}\mid g⟩=\frac{1}{\sqrt{\mid G\mid }}\sum _{\rho \in \stackrel{̂}{G}}\sqrt{{d}_{\rho }}\sum _{i,j=1}^{{d}_{\rho }}{\rho }_{ij}\left(g\right)\mid \rho ij⟩$

or SVG images such that this quantum circuit used in the famous Shor's algorithm:

Voilà!

--update 30/01/2011: you can find my patch for Dotclear 2.2