miniBB is a flat, linear, highly customizable BB. It features MySQL, PostgreSQL, and MSSQL support, table name definitions, color skins, language packs, HTML templates, access control, smilies, search, basic BB codes, member titles and ranks, moderators, email notification, statistics, encrypted cookie logging, IP and user ID tracking and bans, spam protection, "sticky" topics, a powerful admin panel, and more.
FSGuide is a Norton Commander clone used by many hosting firms and individuals for advanced file management through the Web. It features user management (password protection, and access control), advanced file selection dialogs, a multiple file uploader (which can also run any application after uploading), a text viewer, a binary file viewer, a source highlighting viewer, an internal text and binary editor, language support, and much more.
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.