What software or development tools do you use to create and maintain your website?

I'm looking for more great software tools (than the ones listed below that I already use) to not only create and run a website, but to verify and maintain it. All our websites run on Unix servers with php. We use:

1. TopStyle to create and edit html and CSS web pages.
2. Zoom website search engine. You define the output look, search algorithm, and more.
3. FTP Voyager for file ftp work.
4. HTML Validator to verify the html and CSS code are technically correct.
5. Xenu link validator - verifies every link, image, etc on your web site. Reports broken or missing links, redirected, etc. Worst graphics and user interface ever, but it is free, accurate, and fast.
6. Instant Demo Creates professional flash application tutorials for your web site.
7. Web Log Storming Web site log analysis.

What tools do you use? Do they have any quirks? These are the minimum tools I think are necessary (not including a graphics editor) needed by any startup with a web site- assuming they are PC based.

My must haves are:

1. Emacs for editing HTML/CSS/JS.
2. Firebug for debugging all of the above.
3. W3C HTML/CSS validators.
4. Selenium for automated front-end testing.
5. Rsync for file transfers.
6. Gimp for image editing.

Honorable mentions are:

1. Firefox cookie swap plugin for easily changing between various test user accounts and admin accounts.
2. Firefox MeasureIt and ColorZilla plugins for web design tasks.

I'm not a real web developer, but one of the ones I have used is Firebug

You should ask this question on Stack Overflow instead. It's the Q&A site for programming questions. You'll get several excellent answers in a matter of minutes.

I use a text editor(Scite) for HTML. Gimp/Inkscape for images.
WebDeveloper plugin for Firefox for basic HTML tuning and validation.
WordPress for content management.

Here are several suggestions with feedback: StackOverflow