HTTrack is an easy-to-use offline browser utility. It allows you to download a Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. HTTrack arranges the original site's relative link-structure. Simply open a page of the mirrored Web site in your browser, and you can browse the site from link to link, as if you were viewing it online. HTTrack can also update an existing mirrored site, and resume interrupted downloads. WebHTTrack is a Web-based GUI for HTTrack.
The SeaMonkey project is a community effort to develop an all-in-one Internet application suite. It contains an Internet browser, email and newsgroup client with an included Web feed reader, HTML editor, IRC chat, and Web development tools, and is sure to appeal to advanced users, Web developers, and corporate users. It uses much of the Mozilla source code powering such successful siblings as Firefox, Thunderbird, Camino, Sunbird, and Miro.
Kazehakase is a Web browser which aims to provide a user interface that is truly user-friendly and fully customizable. It supports tabbed browsing, a "remote bookmark" feature (through RSS) in a menu or sidebar, a variable UI to adapt to the user's skill level, and customizable mouse gestures and key accelerators.
ArchView can open archive files online without downloading the whole archive, just like normal Web pages. It is very fast since it just fetches a small portion of the archive file from the server. It supports RAR and ZIP formats, and HTTP, FTP, and file: protocols. It can present XUL or HTML interface.