Microsoft, co-founder and chairman
Worth: $76.8bn
Dropped out of: Harvard, Massachusetts
Instead: Founded Microsoft. After supplying the operating system for IBM’s new PC, he refused to transfer the copyright, so he dominated the market when other businesses copied IBM’s hardware.
Bill Gates photographed in 1983 in Washington. Photograph: Doug Wilson/Corbis Photograph: Doug Wilson/ Corbis
Oracle Corporation, co-founder and CEO
Worth: $41bn
Dropped out of: University of Illinois and University of Chicago
Instead: Set up Oracle Systems Communications. By 1986, it was valued at $55m.
Ellison in 1996. Photograph: Andy Watts/Rex Features Photograph: Andy Watts/Rex
Facebook Inc, co-founder, chairman and CEO
Worth: $19bn
Dropped out of: Harvard, Massachusetts
Instead: Created Facebook in one month, launching it in February 2004. Facebook was floated in 2012 at a value of $104bn and announced it had a billion users.
Photograph: Paul Sakuma/AP Photograph: Paul Sakuma/AP
Microsoft, co-founder
Worth: $15bn
Dropped out of: State Washington University
Instead: Started Microsoft with Bill Gates in 1975. After their operating system was used for the IBM network, it became standard for all PCs.
Allen, pictured in 2003. Photograph: Karen Robinson Photograph: Karen Robinson
Dell Inc, founder, chairman and CEO
Worth: $15.3bn
Dropped out of: University of Texas
Instead: Set up "PCs Limited". He employed three people to make the computers. By 1996, Dell Inc was reporting $1m in sales per day.
Dell, pictured in his old dorm at the University of Texas in 1999. Photograph: Harry Cabluck/AP Photograph: Harry Cabluck/AP
Worth: $8.3bn at his death aged 56 in 2011
Dropped out of: Reed College, Oregon
Instead: Spent 18 months sleeping on friends’ floors and getting free meals from the Hare Krishnas. Four years after dropping out, Jobs set up Apple Computer. After resigning from Apple in 1985, Jobs went on to set up NeXT Inc. (later bought by Apple for $427m) and Pixar (worth $7.4bn). Returned to Apple in 1996 to eventually become CEO. Jobs applied – unsuccessfully – to become a civilian astronaut and fly on the space shuttle.
Jobs pictured with an Apple Lisa computer in 1983. Photograph: Ted Thai/Time Life/Getty Images Photograph: Ted Thai/Time Life/Getty Images
PayPal, co-founder
Worth: $8.8bn
Dropped out of: Stanford, California
Instead: Started an email payment system that became PayPal. Went on to found SpaceX, winning a Nasa contract.
Photograph: Sarah Lee for the Guardian Photograph: Sarah Lee for the Guardian
Napster, co-founder
Worth: $2.1bn
Dropped out of: Nope, he never attended university
Instead: Recruited by the CIA, by the end of high school Parker was making $80,000 a year and so never attended university.
Pictured, right, with Snoop Dogg and Alexandra Lenas. Photograph: Kevin Mazur/WireImage Photograph: Kevin Mazur/WireImage
Twitter, co-founder
Worth: $1.5bn
Dropped out of: University of Nebraska
Instead: Started selling tutorial videos to help people get onto the internet. Credited with inventing the term “blogger”. In 2006 he teamed up with Jack Dorsey and Biz Stone to create Twitter.
Photograph: Rick Wilking/Reuters Photograph: Rick Wilking/Reuters
Twitter, executive chairman
Worth: $1.2bn
Dropped out of: New York University
Instead: Moved to California in 1999, came up with the idea for Twitter, built the site and posted the first tweet. Over 10bn messages have followed. Also founder of mobile-based payment system Square.
Photograph: Bloomberg/Getty Images Photograph: Bloomberg/Getty Images
DropBox, co-founder
Worth: $400m
Dropped out of: Massachusetts Institute of Technology
Instead: Left MIT to found DropBox with fellow student Drew Houston in 2007. Starting as just a few lines of code written in a bus station, it has now drawn in over 200 million users.
Photograph: Peter Dasilva/New York Times/Eyevine Photograph: Peter Dasilva/New York Times/Eyevine
Spotify, founder and CEO
Worth: $310m
Dropped out of: Royal Institute of Technology, Stockholm
Instead: Founded his first company at 14; a millionaire by 23. He set up Spotify with Martin Lorentzon in 2008. He was CEO for µTorrent, the most popular BitTorrent client.
Ek pictured in his London office. Photograph: Andrew Testa/Rex Features Photograph: Andrew Testa/Rex Features
Tumblr, founder and CEO
Worth: $300m
Dropped out of: Bronx Science high school
Instead: Started a software consulting company. Karp started work on a microblogging platform, and launched Tumblr in 2007.
Photograph: Don Emmert/AFP/Getty Images Photograph: Don Emmert/AFP/Getty Images
Snapchat, co-founder
Worth: $210m
Dropped out of: Stanford, California
Instead: Started a PhD in physics in 2012, but dropped out after two days to work on Snapchat, which he started a year earlier with Robert Murphy. A year later, an estimated one in 10 Americans have downloaded the Snapchat app.
Picture courtesy of Snapchat Photograph: Picture courtesy of Snapchat
Mashable, founder and CEO
Worth: $95m
Dropped out of: Never attended university
Instead: At 19 he founded Mashable, a news and social media website. By 2012 Time listed him as one of the 100 most influential people.
Cashmore with Richard Branson on a Virgin flight. Photograph: Handout/Getty Images Photograph: Handout/Getty Images
LearnVest, founder
Worth: Has raised $25m funding
Dropped out of: Harvard Business School, Massachusetts
Instead: Using experience gained from her time at Morgan Stanley von Tobel set up a personal finance website for women. Told CBS that when she dropped out: “My family thought I was crazy pants.”
Photograph: Vivien Killilea/Getty Images Photograph: Vivien Killilea/Getty Images
Napster, co-founder
Worth: $7.5m
Dropped out of: Northeastern University, Massachusetts
Instead: Created Napster in 1999 at the age of 19, with the help of Sean Parker who managed to secure the funding. Changed the worldwide sharing of files and within a year had 20 million users.
Fanning at a press conference in 2001. Photograph: Sipa Press/Rex Features Photograph: Sipa Press/Rex Features
