Mosaic was the first widely-distributed graphical browser or viewer for the World Wide Web. It is usually considered to have been the software that introduced the World Wide Web and the Internet to a wide general audience. Once Mosaic was available, the Web virtually exploded in numbers of users and content sites. The success of Mosaic depended on the recent invention and adoption of Hypertext Transfer Protocol by Tim Berners-Lee.)
Mosaic arrived in 1993. Marc Andreessen, then in his early 20s, is credited with inventing or leading the development of Mosaic. He developed it at the National Center for Supercomputing Applications (NCSA) at the University of Illinois in Urbana, Illinois. Andreessen and others went on to become part of Netscape Communications, originally called Mosaic Communications. Netscape then produced what was, for a while, the world's most popular browser, Netscape Navigator.
The original Mosaic, now in a later version, has since been licensed for commercial use and is provided to users by several Internet access providers.