Latex formula support is provided via itex2MML and Jacques Distler’s excellent WordPress plugin. Frederick Leitner modified these for WordPress 2.0.0/2.0.1. Unfortunately, WordPress 2.6 is different again, so I had to tweak a bit further. Here are instructions:
- Install itex2MML and the itex2MML WordPress plugin.
 - Install the content negotiation plugin.
 - Apply the diff formatting.php.diff to get formatting.php. This is a modified version of the diff provided by Leitner. Note that I had to remove the “|math|” bit from allblocks to prevent inline math from breaking. Some of the cases probably could use “|math|”, so this may need additional modification.
 - Modify the doctype in wp-content/themes/…/header.php to allow general mathml: ``
 - (Update) Change the {1,8} ranges in formatting.php to at least {1,10} in order to treat 
→correctly. 
Warning: itex2MML produces MathML, which is not readable by a many browsers. Hopefully this situation will improve, but until then this blog will be nonportable.