That "Hello World" code from yesterday (dammit... I missed a trick there... it shoulda been "G'day World", for this blog, shouldn't it!) was written using Notepad++, as I didn't have an IDE installed at that point in time.
My initial instincts for an IDE was to just use Zend Studio, as my understanding was that it was considered where it's at as far as PHP dev environments go. Then Andrew Myers recommended Netbeans, and I also googled around to see what else was on offer.
Most of what I found was just people going "[name of IDE] is best", without any sort of qualification of why it's the best. Basically I think they are more often than not confusing "best" with "their favourite" which is not the same thing at all, and not any sort of yardstick for anyone else to use. However Netbeans did keep coming up over and over again, which was interesting. More often than Zend, too.
Other offerings which were mentioned favourably were Aptana and DreamWeaver, but I have discounted those options. Firstly if I'm gonna use an Eclipse plug-in (ie: Aptana), then I'm not going to use one that is primarily for HTML/CSS which also happens to do PHP; I'm gonna pick one that's specifically for PHP (eg: Zend). I discounted DW because I'd have to pay for it. And I used DW years ago and disliked it. It's come a long way since then, but I don't really care.
There were stacks of other options mentioned by people, but life's too short to go through all of them so I just shrugged.
Then I found an objective-seeming comparison of PHP IDEs / editors, which scored various options and seemed to be a fairly disempassioned assessment. It mentioned Netbeans more often more favourably than the others, so that has me slightly swayed.
One consideration I have is that I've been using Eclipse for years, and I really like it. And Zend is based on Eclipse. And I already had it downloaded and installed (after y/day's coding) as that's what I figured I'd be using.
But now I think I will leave Zend sitting in the background, and give Netbeans a go. I'm just installing it now, but will have to do it smartly as I need to start heading to the Belgian beer cafe (PDF) down on the waterfront to have lunch with some mates.
Andrew, I will blame you if I don't like it. And will claim back those beers I owe you ;-) (not really).