Age: 25
Company: Mozilla
Net Worth: $150 Million
What's the Deal?: In 2004, his Mozilla Firefox web browser bumrushed the Internet market share and pulled in over 100 million downloads in less than a year, making him a millionaire at just 19 years old. Though he shares ownership with partner-in-crime David Hyatt, you can split his net worth in half and he still brings in more than a majority of his entrepreneurial peers.