Amazon’s A9 subsidiary has released A9 Toolbar for the Mozilla Foundation’s Firefox Web browser, reports CNET News.com. The toolbar offers the same features to users of the Mozilla open-source software as it does for other browsers, including the “bookmarks” function, which lets users save favorite Web sites and access them from any PC, and “diary,” which lets users save notes to themselves. The A9 toolbar is compatible with Mac OS, Linux and Windows.