What are the industry standard tools and SDKs for PHP developers?

[Maxx The Axe]

I've spent most of my life writing VB and .NET applications, and only recently have I started to tinker with PHP. I'd like to know what IDE's and such are favored by professionals who turn out websites based on the LAMP platform.

I'm running Windows XP myself, so if I can get suggestions that don't involve a reformat to Ubuntu, that would be rockin'. Freeware is always nice to know also.

Thanks in advance.