I started using this a couple weeks ago. It's awesome, and very extensible if you know Python.
Dreamweaver... Are you guys serious?
While some people mean "Design View" only when they say they use Dreamweaver, most only use "Code View". DW is one of the "few" code editors that has a comprehensive "suggest" & "complete" library for HTML and PHP tags and functions. Since a large portion of people on WF use PHP and HTML to build websites, you'll see it suggested a lot.
what software do you use for website designing.
For a long time I used Dreamweaver to edit my HTML, JS, and CSS code, and used Photoshop to slice up the layout. I then moved to using Fireworks for the layout since I found CS4 & 5 to be a lot more efficient. Photoshop just doesn't handle vectors and large text areas well like Fireworks (which is handy when doing Lipsum text for filler).
However, since moving to Linux Mint instead of Windows, I found Geany (there's a windows and mac version) to be really extensible and you can make your own plugins. So I used that.
Recently I've been using Sublime Text 2 (in beta & free if you want that) after Dchuk suggested it to me. It's really handy. I'm still learning my way around its extensive advanced tool list, but its split views and whole document thumbnail selection alone make it really easy to navigate your files and compare revisions.
It really just depends on what level you're at as a programmer (such as your workflow and using git or svn vs just ftp) and how many different languages you know and use on a regular basis.