Since MacGDBp from bluestatic.org seems to be discontinued, is there another way to debug PHP applications with xDebug using a a standalone app for Mac OS X?
I use TextMate as my primary editor, and I'd rather not switch to NetBeans or Eclipse.
Not sure where you read that it was discontinued. A new beta version was just released:
https://www.bluestatic.org/blog/2011/01/15/macgdbp-1-4-beta-2/