(To be improved... got problems with image upload at the moment ... :/ )
After one year of very little PHP / MediaWiki / SMW coding, the time finally has came to get going a bit agian. So first thing was getting a decent PHP IDE with a debugger, up running.
Last year I used Eclipse with PDT (PHP Development Tools) and Xdebug. The installation was a bit tricky though and I had to stay with Eclipse Galileo due to some bugs, but now things have changed. With PDT 2.2 and the latest XDebug (2.1.1), installing on Ubuntu is a snap.
This is what should work: