Komodo is a powerful IDE with support for Ruby, Perl, PHP, Python and more.
The source code editor provides all the features you'd expect, and then adds several more for good measure. So you get accurate syntax colouring for dozens of languages, code completion, intelligent auto-indenting, Find and Replace with regular expression support, code folding, and tabbed editing, amongst many others.
And there are all kinds of handy productivity tweaks on offer. If you're working on a large project, for instance, then it's often easy to get lost as you jump around from module to module. Komodo IDE's Editor History, though, remembers where you've been, so it's quick and easy to jump back to some crucial point in your code.
You also get local or remote debugging for five languages: PHP 4.4 – 5.3. Python 2.4 – 3.1, Perl 5.8 – 5.12, Ruby 1.8 – 1.9, Tcl 8.4 – 8.6. You're able to set breakpoints on files or lines, on function calls or returns, on exception, according to a variable's value, and more. There's support for stepping through and breaking multiple thread, and the HTTP Inspector allows you to view browser-server communications, breaking on requests or responses, then submit modified traffic to view the results.
A host of tools allow source code control integration, help with code formatting, provide interactive shells (for Python, Ruby or Perl), and more.
And if, for some reason, Komodo IDE still doesn't quite work as you'd like, then it's fully customisable, and supports a host of Firefox-type addons that can extend the program with many new capabilities.