I am very happy with Mac OS X 64–bit Zend debugger and Zend Studio. It is a perfect combination for the serious PHP developer. However I miss certain features of XDebug, such as a great error reporting.
Some years ago I tried running Zend Debugger with XDebug and it did not go: the server simply refused to start because of PHP initialization error. It was a Zend precaution against third party extensions that may prevent debugging.
Today I decided to try again and I found that it works! The only requirement is that XDebug is loaded before the Zend debugger. It will not be possible to debug with XDebug but profiling and enhanced error reporting works perfectly.
Whether it is accidental or not, I have no idea. But I really like that Zend allowed XDebug loading in parallel with Zend debugger. It makes developer's life even better.
Thank you, Zend, again!