Hey,
An interesting question to ask here is why the WMF is still running PHP 5.3, and what the plans are for upgrading to 5.4.
In general MW seems to work just fine on PHP 5.4 or 5.5. One possible exception being that update.php appears to have been broken with PHP 5.5 yesterday: https://bugzilla.wikimedia.org/show_bug.cgi?id=49819
Cheers
-- Jeroen De Dauw http://www.bn2vs.com Don't panic. Don't be evil. ~=[,,_,,]:3 --