Unicode support for PHP 5 and above (including PHP 6)
Various (mainly minor) changes to Web DOM Core spec and a (Currently incomplete) test suite.
Aren't stopwatches fun?
Habari plugin to give you random sayings of gsnedders
GZIP (RFC1592) decoder for PHP
1:1 implementation of HTML 5 algorithms with some tests
What is a bug?
HTML document postprocessor, which does approximately the same as the W3C CSS WG Postprocessor. You probably actually want Ms2ger's fork of this, because that's actually maintained.