Emacs/W3 is a web browser written entirely in Emacs Lisp. As such, it has unique strengths and drawbacks. The strengths are related to its integration with Emacs; the drawbacks are that it is relatively slow and sometimes blocks your editing session. Development has been dormant for a couple of years, so expect bugs due to bit rot. Please report bugs either to the mailing list (see below) or to the bug tracker.
Currently, it is recommended to use the Git version. Emacs/W3 is hosted on Savannah, and you can use the following command to check out a copy:
git clone git://git.sv.gnu.org/w3.git
Or if your firewall only allows HTTP access, you can use the slower equivalent:
git clone http://git.sv.gnu.org/r/w3.git
There are two mailing lists, w3-announce and w3-dev. You can also use Gmane to read them through NNTP or with a web browser: gmane.emacs.w3.devel and gmane.emacs.w3.announce.
I (Magnus Henoch, the new maintainer) have only been fixing bugs so far, not redesigning anything or looking at the big picture, so I'm not sure whether the following applies. For now, I'm not removing it.
This is a very rough pass at the web site (by the original author) just to get some thoughts down and accessible to more people. The project page @ Savannah has a fairly detailed task list. A brief description of each component and a list of questions and/or resources related to it may be found in the following documents.