Dreamweaver CS5 users—
Adobe released the Adobe® Dreamweaver® CS5 HTML5 Pack extension. It provides initial support for HTML5 and CSS3 within Adobe Dreamweaver CS5. It’s a good way to start creating HTML5 pages and CSS3 styles.
HTML5 and CSS3 are not in their final form yet, but this extension provides support for some of the currently implemented features. You can check out these features and download this new Dreamweaver CS5 Extension at this link on the Adobe Labs site.