Looking for a powerful tool for creating standards-compliant sites? Consider TopStyle, written by the creator of HomeSite, the world famous HTML-editor.
You can edit your HTML, XHTML and CSS in a single program. Preview CSS while you write it. Style Checker to validate style sheets against multiple browsers. Style Upgrade tool to quickly replace all outdated HTML code. Site Reports to see at-a-glance where styles are used in your site.