Silicon Graphics founder who cold-emailed Andreessen in 1994, funded Mosaic Communications/Netscape with roughly $3-4 million, and provided the business credibility a 22-year-old programmer couldn't have supplied alone.

Timeframe: 1994-1998

Co-founded Loudcloud/Opsware and later Andreessen Horowitz with Andreessen; led operations and CEO duties through Loudcloud's near-collapse and the Opsware turnaround, and remains his general partner at a16z today.

Timeframe: 1999-present

Full-time NCSA programmer whose coding skill was central to building the actual Mosaic browser alongside Andreessen in 1992-1993.

Timeframe: 1992-1994

Married Andreessen in 2006, connecting him to the Arrillaga family's Silicon Valley real estate wealth and network; co-runs the couple's philanthropic foundation and is mother to their son.

Timeframe: 2006-present

Brought in as Netscape's CEO in January 1995 to provide seasoned executive management during the company's hypergrowth phase and IPO.

Timeframe: 1995-1999