The www is an example application that comes with libwww - the W3C Sample Code Library. It is a character based Web browser developed for use on terminals. It uses the libwww HTTP/1.1 implementation including a full HTTP/1.1 persistent cache, history lists etc.
The computers you meet on today's desktops are equipped with very fast processors (usually over 1GHz) and a few hundreds megs of RAM. Even very complicated and resource-consuming applications don't cause any problems for them. However, there are still old machines around which can't easily run such programs. They either don't launch them at all or run so slowly that sensible work can't be performed.