Microsoft has released its developer toolbar for Internet Explorer 6, designed to make developing and previewing websites in IE even easier. The features, as described on the download site:

• Explore and modify the document object model (DOM) of a web page.
• Locate and select specific elements on a web page through a variety of techniques.
• Selectively disable Internet Explorer settings.
  View HTML object class names, ID’s, and details such as link paths, tab index values, and access keys.
• Outline tables, table cells, images, or selected tags.
• Validate HTML, CSS, WAI, and RSS web feed links.
• Display image dimensions, file sizes, path information, and alternate (ALT) text.
• Immediately resize the browser window to 800×600 or a custom size.
• Selectively clear the browser cache and saved cookies. Choose from all objects or those associated with a given domain.
• Choose direct links to W3C specification references, the Internet Explorer team weblog (blog), and other resources.
  Display a fully featured design ruler to help accurately align objects on your pages.

The Developer Toolbar can be pinned to the Internet Explorer browser window or floated separately.