Marc Andreessen co-created NCSA Mosaic, the web browser that brought the World Wide Web to a mass audience. According to the National Center for Supercomputing Applications (NCSA) at the University of Illinois, where he was a student employee, “Marc Andreessen and Eric Bina” worked on the project that became Mosaic. NCSA describes Mosaic as “the first published browser that automatically displayed pictures along with text, as in the pages of a magazine layout or an illustrated book,” a design choice that made the Web approachable for ordinary people.
The impact NCSA records is striking. The center reports that by December 1993 Mosaic appeared on the cover of the New York Times business section, which called it “the first ‘killer app’ of network computing — an applications program so different and so obviously useful that it can create a new industry from scratch.” NCSA notes that Mosaic transformed the Web “from the domain of scientists and hackers to a cultural phenomenon that captured the interest of the masses.”
After leaving NCSA, Andreessen helped found the company that became Netscape, which built the Navigator browser and turned the Web into a commercial platform. Navigator’s rise set up the rivalry with Microsoft’s Internet Explorer that defined the first browser war.
In his later career Andreessen became a prominent venture capitalist, co-founding the firm Andreessen Horowitz. He remains one of the few figures who both wrote foundational web software and went on to fund a generation of internet companies.