It is true that many tech executives live in the lap of luxury, quick to splurge on yachts and mega-mansions.

However, there are some exceptions: some of them choose a more frugal way of living, despite being extremely rich.

Business Insider, a US business and technology news website, has rounded up 10 tech executives who have made billions with their companies, yet they’ve chosen lives of frugality and charity.

1. David Cheriton, Stanford professor

Net worth: $3 billion

2. Charlie Ergen, chairman of Dish Network

Net worth: $16.3 billion

3. Pierre Omidyar, founder and chairman of eBay

Net worth: $8.1 billion

4. David Karp, founder and CEO of Tumblr

Net worth: at least $200 million

5. Azim Premji, chairman of Wipro Limited

Net worth: $15.4 billion

6. Mark Zuckerberg, founder and CEO of Facebook

Net worth: $15.4 billion

7. Jan Koum, founder of WhatsApp

Net worth: $6.8 billion

8. Tim Cook, CEO of Apple

Net worth: rumored to be as much as $400 million

9. Tony Hsieh, CEO of Zappos

Net worth: close to $1 billion

10. Sergey Brin, cofounder of Google

Net worth: $30.9 billion