Emacs/W3 - A web browser that runs under GNU Emacs. - http://www.gnu.org/software/w3/
zsync - An implementation of rsync over HTTP. - http://zsync.moria.org.uk/
K-Meleon - A Windows web browser based on the gecko layout engine. - http://kmeleon.sourceforge.net/
Galeon - A GNOME web browser based on the gecko layout engine. - http://galeon.sourceforge.net/
ComClear - A history cleaner for Netscape Navigator and Communicator. (C) [GNU/Linux, Unix, Windows] - http://freshmeat.net/projects/comclear/
Konqueror - A web browser with HTML4.0 compliance, supporting Java applets, JavaScript, CSS1 and (partially) CSS2, as well as Netscape plugins. (C++) [GNU/Linux] - http://www.konqueror.org/