Here are some things that I look for in an IDE:
- Basics: Syntax highlighting, code folding, block indentation, bracket matching, etc. These are little things that help you out when you're programming. Oh, and make sure it intelligently handles tabs. If I press backspace, it deletes one character. Not 20. See PhpEd for an example of retarded tab management.
- Minimalist: Don't get in my way. I want to code without stupid paper clips or something popping up like, "It looks like you're writing an HTML file, let me help!" While code-completion is nice, don't be excessive about it. In PHP where you tend to have hundreds of variables everywhere, I don't want the code-completion thing giving me a list of twenty different things when I type "$num" or automatically finishing a word when I type something like "ret" (see Netbeans).
- Directory Tree: On the left side, give me a directory tree. I've spent enough time developing with Kate or KDevelop to know that having to double click ".." several times and then find the folder I want is very annoying.
- Built-in FTP: Mainly for web development IDEs. Many of the Linux FTP programs are fairly slow to use. gFTP doesn't use tree structure and so every time you want to move to a different folder, it's a bit of work. Even worse is the command-line sftp, with all the cd this and lls that, way too much typing to make me productive. I just want to hit Ctrl+Shift+U (or whatever your upload shortcut is) and be done with it.
Quanta fits all of these. There are a few things that I would change, like importing files and folders into the project is a little clunky and their FTP is sometimes a bit clunky for uploading groups of files, but other than that it pretty much hits everything on the nose.
The main problem that I had with Quanta is that it is for KDE only, so if you want to install it on Ubuntu you have to install all the kde-base libs. Fortunately I use a lot of other KDE programs like Kate and KolourPaint, so it's all good. Second main problem is that by default (unless you're under KDE) you don't have the SFTP protocol installed, so you're limited to basic protocols like file:// or ftp://. With a little help from our friend Google I figured out you need to install the kio-base libs. It wasn't a huge problem, but anytime you must consult Google is considered wasted time in my opinion.
A note to emacs/vi users: Screw off. I want to spend my time coding instead of memorizing thousands of commands.