jeepin81:
I currently use a slew of editors:
Zend Studio 5.5.0
Zend Studio Neon beta (Based on Eclipse)
Eclipse
NuSphere PhpED 5.2
EditPlus 2.x & 3.x (currently in private beta)
E Texteditor (Textmate for Windows)
They all work on Vista. None have been "Vista Certified" as they don't need to be. Zend, Zend Neon, Eclipse, Eclipse PDT all use the Java language, so as long as your Java is able to run on Vista, you can run any of those 4. NuSphere's PhpED has run on Vista since it's 5.0 days. It had bugs, but they were fixed.
EditPlus and E-Texteditor are two regular text-editors with syntax highlighting. EditPlus 2 may have a minor issue during install; however, after that you're fine. EditPlus 3 works splendidly under Vista x64 Ultimate (for me). E-Texteditor works well too, bringing in support from Cygwin 😉
There are others that will work, like Notepad++ or Notepad2. But as I said before, none are "Vista Certified" because that's not possible in software. Vista will run almost any program. Heck, I can still play StarCraft and StarCraft: Broodwar on my Vista x64 machine!! So I can't see why running some slightly older software would hurt 😉