use MySQL, 'mysql' or 'mysqli' may work.
- GD Image manipulation (scaling).
- mbstring For handling Unicode (UTF-8) encoded strings.
-- bcmath or gmp For Salmon signatures (part of OStatus)
+- bcmath or gmp For Salmon signatures (part of OStatus).
Better performance
------------------
Sphinx server to serve the search queries.
- gettext For multiple languages. Default on many PHP installs;
will be emulated if not present.
+- exif For thumbnails to be properly oriented.
You may also experience better performance from your site if you install
a PHP bytecode cache/accelerator. Currently the recommended cache module