Mosaic is probably the most widely used and flexible WWW browser, it is available for X-windows, Macintosh and Microsoft Windows and it is free. Mosaic under X also uses extra programs to view images (xv), to play sounds and movies and so on. You have to install all these programs if you want full access to all types of hypermedia.
Mosaic requires a terminal/operating system that supports windows of some sort. There are several browsers that will work from a vt100 terminal and these can be useful if you are only interested in the text and no images, one of the best non-graphical browsers for the WWW is lynx. You can find out about these and other browsers from the CERN WWW site.