HTML Purifier 3.1.0 is the second release series for HTML Purifier on PHP 5
as well as a security update related to URIs. It shifts over to using
autoload, and also includes support for the !important CSS modifier,
display and visibility CSS properties with %CSS.AllowTricky, marquee with
%HTML.Proprietary (had you scared for a moment, hmm?), a kses() wrapper,
%CSS.AllowedProperties, %HTML.ForbiddenAttributes and
%HTML.ForbiddenElements and a totally revamped ConfigDoc system. Since the
release candidate, there have also been a number of stability fixes such as
improved URI escaping, a change in serializer ID format, and a relaxed
format for %HTML.Allowed. And as always, numerous bugfixes.