per node type (since it doesn't always work), and allow users without
'view revisions' permissions to still use the 'Preview changes' button.

Changed handling of diff during editing, so show preview works for file attachments and revisioned taxonomy

rollback node type specific tab visibility. cmenu.inc does not allow that for contextual items. will return for D6

module. Now based on the GPL'ed mediawiki PHP diff engine from phpwiki.
Instead of a separate diff tab, this overrides the revisions tab and
provides radio buttons to select which revisions to view diffs between.
Shows diffs in unfiltered, raw node data, instead of rendered HTML.
Also, provides a hook_diff() for modules to define any parts of a node
that they control with revisions (e.g. file uploads, etc) for display.

update PEAR to latest. i fixed paths for include files and commented out _encode() method in inline.php because it was encoding all output. hope that doesn't disturb the diffs

at minumum, you should allow the <ins> and <del> HTML tags in your Filterd HTML input format. you might want to shut off the HTML filter just to evaluatre this module
this is almost identical to one in alaa's sandbox. i just updated it. needs more work i thinkm but it is pretty interesting already