Tim Berners-Lee, who invented the World Wide Web together with Robert Cailliau, built the first working prototype in late 1990 and early 1991. That first prototype consisted of a web browser for the NeXTStep operating system. This first web browser, which was named "WorldWideWeb," had a graphical user interface and would be recognizable to most people today as a web browser. However, WorldWideWeb did not support graphics embedded in pages when it was first released.
The first graphical web browser to become truly popular and captured the imagination of the public was NCSA Mosaic. Developed by Marc Andreessen, Jamie Zawinski and others who later went on to create the Netscape browser, NCSA Mosaic was the first to be available for Microsoft Windows, the Macintosh, and the Unix X Window System, which made it possible to bring the web to the average user. The first version appeared in March 1993. The "inline images," such as the boutell.com logo at the top of this page, that are an integral part of almost every web page today were introduced by NCSA Mosaic 2.0, in January of 1994. Mosaic 2.0 also introduced forms.