The tidy extension now works in PHP4 for most tasks, only the parsing
abilities of the extension are not available (ZE2 only). The OO portions
of the extension have been completely re-written and are now stable and
work quite well.
The way all tidy functions work has also changed slightly. Instead of
calling tidy_create() to create a tidy resource, the tidy resource is
stored internally and used as needed. Thus, all tidy functions no longer
need the initial $tidy parameter to function. If you'd like to reset
tidy to an initial state, you can still call tidy_create(). This change
was done to make tidy faster per-request. Special Thanks to Ilia
Alshanetsky for his work in this respect (among other things)!