Marc Andreessen has joined eBay's Board of Directors, effective immediately. An entrepreneur, investor, and blogger, Andreessen's current focus is Ning, a next-generation platform for social networking.

As an undergraduate at the University of Illinois at Urbana-Champaign, Andreessen and Eric Bina co-created the Mosaic Internet browser. Mosaic was the first widely-used browser that helped transform the Internet from a niche environment for academics and researchers into the state-of-the-art global multimedia network. He co-founded Netscape with Jim Clark in 1994, which pioneered the commercial Internet and invented or co-invented such technologies as Javascript, SSL and RSS, and helped Internet standards such as HTML, HTTP, Java,SMTP, IMPA and LDAP become commercially mainstream. Netscape was acquired in 1998 by America Online. Andreessen subsequently served as AOL's Chief Technology Officer until September 1999.

"Marc is a true visionary whose experience will be invaluable to eBay," said John Donahoe, president and chief executive officer of eBay Inc. "We look forward to learning from Marc's insights and expertise as we drive further innovation on our platform, invest in growth opportunities and develop technology that will further benefit our customers, build powerful communities and enhance e-commerce."

Andreessen has served as an angel investor and advisor to startups including Digg, Del.icio.us, Twitter, Qik, Aliph/Jawbone, LinkedIn, Meebo, Netvibes, Outside.in, Revision 3, Fon, Funny or Die, Scribd, and Wikia.

He currently serves on the boards of Facebook, Stanford Hospital in Palo Alto, California and Room to Read in San Francisco, California.