Vuze, originally known as Azureus, is a BitTorrent client written in Java, which makes it rather platform independent. The Eclipse SWT toolkit is used for providing the user interface functionality.
The BitTorrent protocol is a new way of exchanging or distributing data over the internet. Downloading also means uploading, and the amounts of each are linked, to ensure fairness and rapidity in the spread of the file at hand.

HTTrack is a free and open source Web crawler and offline browser, developed by Xavier Roche and licensed under the GNU General Public License.

FileZilla is free, open source, cross-platform FTP software, consisting of FileZilla Client and FileZilla Server. Binaries are available for Windows, Linux, and Mac OS X. It supports FTP, SFTP, and FTPS (FTP over SSL/TLS). As of 5 March 2009, FileZilla Client was the 5th most popular download of all time from SourceForge.net.
FileZilla Server is a sister product of FileZilla Client. It is an FTP server supported by the same project and features support for FTP and FTP over SSL/TLS.
FileZilla's source code is hosted on SourceForge.net. The project was featured as Project of the Month in November 2003

Mozilla Thunderbird is a free, open source, cross-platform e-mail and news client developed by the Mozilla Foundation. The project strategy is modeled after Mozilla Firefox, a project aimed at creating a web browser. On December 7, 2004, version 1.0 was released, and received over 500,000 downloads in its first three days of release, and 1,000,000 in 10 days.