In article AD14DF6D-770C-4287-8D37-5797D146C078@xs4all.nl, Siebrand Mazeland s.mazeland@xs4all.nl writes:
PhpStorm can be used by Mediawiki developers for free. It has a one month trial I believe. If you want to continue using it, please contact Sam Reed for the serial number.
Our current license key expires mid 2013. I do not yet know if the author of phpstorm will extend its free for use program after that.
I was going to recommend PhpStorm as well. It has refactoring support.
JetBrains (the makers of PhpStorm) has a program that makes licenses available to open source projects. My little open source project written in PHP was able to obtain a license, so I see no reason why MediaWiki wouldn't get their license renewed.