See also: Web browsers
The name is Japanese for "See the WWW". So in English, the name of this browser would be something like "stw3".
w3m can also be used as a pager (like less or more), a HTML -> plain text converter, and can be significantly extended by using CGI scripts, which can be used directly from the hard drive.
Source and patches can be downloaded at http://www2u.biglobe.ne.jp/~hsaka/w3m/patch/, the only way I found to get the async patch to work (it's 10000+ lines) was to get the patched gentoo .tbz, which should work on all unix-like systems.
Also if your display looks weird when using w3m set the default charset to ISO-8859-1