What is the oldest web browser?

The first browser was "WorldWideWeb", soon followed by Mosaic and Lynx (which is still in use).

Mosaic, also know as Netscape went out of business because of Microsoft; you know browser wars.

Netscape made a new browser, know as Mozilla (1998), which eventually provided the basis for Firefox in 2004. AOL is now in charge of the official Netscape. http://en.wikipedia.org/wiki/Mosaic_(web_browser)