I've got a project to do and it requires that I use PHP (typically an ASP.NET developer), so I'm looking for a good IDE to install on my home PC to do some development & debugging.

Currently I am using Windows Vista 64-bit (Ultimate), and if possible I would like to install the least invasive software (meaning, if I can, no Apache - bad enough I have IIS running).

Anyways, given that I am new in this field I was wondering what most people would recommend for a PHP IDE for development (not trying to host the project - just develop/debug).

Any advice would be much appreciated...
Thanks,