Thunderbird is a total redesign of the Mozilla mail component to produce a cross-platform, stand-alone mail application using the XUL user interface language. It has many new features, among them the ability to customize your toolbars the way you want them. a new look and feel with a large number of downloadable themes which alter the appearance of the client, and the ability to add UI extensions.
SEO Profesional Toolbar offers many SEO-related tools in one place. It can display PageRank, S-Rank, and the number of backlinks for visited pages. It stores the history of ranks for selected sites. It can highlight words, links, view the number of words, and more. The history of ranks and back-links is stored in a database, therefore you may watch how your pages evolve in time. All are equipped with beautiful colorful charts. You can view observed domains in the sidebar and check their ranks without even visiting them. The extension also includes a customizable list of handy SEO-related links. All this is packed together with a search tool for enumerating and highlighting words and different types of links.