I use Zend Studio 5.x , the newer versions are on Eclipse and I couldn't get used to it. Crimson Editor is also pretty good and it's free last time I checked. If you're on a mac Coda is pretty good too, but it's not free, but it's cheaper than Zend Studio. Also they have an iPad app so you can code on your iPad, pretty nifty UI for it too.
Sorry I thought he is asking for complete development environment. Please check this link for more details http://php-editor-review.toptenreviews.com/
What about Bluefish? It is free and open source and I have heard it was pretty good, maybe too simple compared to others.
Too complex IMHO, filling the screen with crap you shouldn't need in the first place, most of which is exactly the type of lame duck crutches that just make people sloppy programmers. Stupid malfing space wasting sidebar and toolbars, idiotic code generation garbage, no way to turn off tabs or *SHOCK* have things in separate windows where they are actually useful... Of course that they call it's 4.3 megabytes "lightweight" when it needs another 7 megabyte library to even function (Said library -- gtk -- probably not even having a reason to exist if X11 wasn't such a pile of ****) doesn't exactly inspire confidence. Basically a poster child for everything that's "wrong" with needlessly bloated "programmers editors"... and I say the same thing about "Zend Studio", "Eclipse", "Coffeecup", etc, etc. After five minutes of struggling with those idiotic useless garbage, I'd rather use vanilla notepad -- more useful because it doesn't get in my {string of expletives omitted} way!
I will check myself all 3 php editors: Bluefish, Netbeans and Eclipse and I will see which is the best of them.
I will admit, I did not read through the rest of the thread but to throw my 2 cents in... there are two I would recommend: PhpStorm phpDesigner Personally, I use and love both, but if pushed to recommend one over the other, it would be PhpStorm.
As a php developer, i would like to suggest you notepad++ and Dreamweaver. Both are very easy to use. From long times, I use Dreamweaver but notepad++ is another best option for writing PHP script.
I used Notepad++ and I can say its a little too simple for more complicated job. I would prefer to use Bluefish instead. But I am going to work on Netbeans or Eclipse for PHP.
I'll be honest, I still use Notepad for most of my web development. I occasionally use Notepad++ depending what I'm going.
I first start on dreamweaver, then move to notepad++ and wonder why I paid for Dreamweaver in the first place... then move on to eclipse until now and never look back. Is eclipse is the best? Far from it, its a memory hog (16 GB of memory can still not enough, amazing isnt it?) especially when editing javascript due to memory leak. when typing . in while creating a javascript editor pause for a second or more... Why stick on it? mostly just habit and its free...
I don't understand what you said about eclipse and memory of 16GB. I've installed eclipse which used only about 170 MB on my hard disk.