libass (0.9.7)
 * Build system fixes
 * Fixed cache lookup and overload problems
 * All globals have been eliminated, libass is reentrant
 * Dynamically allocate glyph and line buffers
 * Fix up stroking of big borders
 * Support empty lines (\N\N)
 * Support for the following override tags:
   \fax, \fay, \xshad, \yshad, \ybord, \xbord, \iclip, \u, \s, \p, \pbo
 * Full subpixel accuracy for positioning
 * PAR and rotation correction for EOSD rendering
 * Drawing mode (including vector \clip and \iclip)
 * Fixed a few memory leaks
 * Removed MPlayer compatibility code
 * Introduced message handling callback
 * Various fixes to match VSFilter quirks and Windows font metrics
 * Lots of bugfixes

LibASS (0.9.6)
 * Various fixes and updates to match VSFilter renderer.
 * Support \blur tag and ScaledBordersAndShadow property.
 * Fractional arguments and subpixel accuracy.
 * Keep positions when pan-and-scan is used.
 * Lots of bugfixes and other changes.

LibASS (0.9.5)
 * Support '=' and '.' in style name in arguments to ass_set_style_overrides().
 * Allow overriding [Script Info] parameters with ass_set_style_overrides().
 * Add workarounds for some buggy fonts.
 * Remove buggy workarounds for some other fonts.
 * Fixed ass_set_line_spacing() (was broken before).
 * Negative margin sizes are now used for image cropping.
 * Better handling of behind-the-camera objects.
 * Case insensitive parsing of SSA/ASS section headers.
 * Improved font matching.
 * When 2 styles have the same name, the later one is used.
 * Fixed several other bugs.