#36 Evan Williams
Company: Medium
Age: 41
Evan ("Ev") Williams has quite the track record. He sold his first company, Blogger, to Google for millions in 2003, and is about to cash in on Twitter's IPO. The co-founder and former CEO's 15% stake in the company could translate into $1.5 billion.
His latest endeavor, Medium, is a fiction and nonfiction publishing platform that promises to reinvent the way we read. Articles are labeled by how long they take to read—and you won't find any under 140 characters.
Born and raised on a farm in central Nebraska, Williams enjoys long walks in the city, tofu, and burgundy.
#35 Amanda Hesser
Company: Food52
Age: ~42
Amanda Hesser cooked up Food52, a culinary website that recently launched an e-commerce section, out of a need for community in the foodie universe. She has been named one of the 50 most influential women in food by Gourmet, and had a cameo as herself in the movie "Julie & Julia."
Hesser was a New York Times food columnist and editor for more than a decade, and wrote the award-winning books "The Essential New York Times Cookbook," "Cooking for Mr. Latte," and "The Cook and the Gardner."
#34 Patrick Collison
Company: Stripe
Age: 25
This Irish transplant has taken Silicon Valley by storm with the payments company Stripe, which he co-founded with his brother. Stripe processes millions of dollars every day for companies including Foursquare and Reddit, and has raised $40 million in funding after attracting the interests of Peter Thiel, Elon Musk, and Sequoia Capital.
Patrick Collison took a computer course in the University of Limerick at age 8, and dropped out of MIT.
#33 Alexa Andrzejewski
Company: Foodspotting
Age: 30
Alexa Andrzejewski first came up with the idea for Foodspotting because she couldn’t find good Okonomiyaki or bacon milkshakes in San Francisco. Her website and mobile app finds and recommends dishes instead of just restaurants.
Andrzejewski certainly brought home the bacon earlier this year, when Foodspotting sold to OpenTable in January for $10 million.
Alexa’s first food-related venture was making and selling miniature food for American Girl dolls when she was 8.
#32 Darian Shirazi
Company: Radius
Age: ~28
Once Facebook's first intern, Darian Shirazi ditched the Social Network after a year and a half and founded Radius, a software manufacturer that helps marketers reach small businesses.
This Berkeley dropout and jokester originally named the company "Fwix" because he wanted a "cheap, available, and short domain name" and set up office in a Bay Area house with three friends. This year, Radius raised $12.4 million in funding.
His advice for getting in touch with him? "Smoke signals."
#31 Carter Cleveland
Company: Art.sy
Age: ~26
While studying computer science at Princeton, Carter Cleveland co-founded Art.sy, which uses Artificial Intelligence to match collectors' preferences with artworks online. He calls it "Pandora for the fine art world."
Cleveland played Varsity squash and performed with the diSiac Dance Company while at Princeton.
#30 Chris Poole
Company: 4chan
Age: ~25
Chris Poole, known by his online pseudonym "moot," is a juggernaut of the Internet rebels community. He started 4chan.org when he was 15, and it's since become hugely influential — the birthplace of LOLcats, Rickrolling, Occupy Wall Street, and Anonymous, and just a little smaller than NYT.com in terms of traffic.
His latest endeavors include the online image-based message board Canv.as and iPad drawing app DrawQuest.
#29 Kelsey Falter
Company: PopTip
Age: ~23
Kelsey Falter has always itched to launch a startup. She grew up stuffing envelopes for her mother's business, bought her first domain name at age 8, and left college a few credits shy of a degree to pursue her passion.
Her current company, PopTip, helps businesses and organizations get instant feedback via social networks by asking questions and sorting through the results. It's like a Twitter-produced Quora.
#28 Jessica O. Matthews
Company: Uncharted Play
Age: ~26
Jessica O. Matthews and her Harvard classmate Julia Silverman dreamed up Uncharted Play's flagship product, the sOccket, in their junior year engineering class. It's a soccer ball that acts as a portable generator — a mechanism inside harnesses energy during play and stores it in a battery that can be used later to power devices.
Matthews' family is from Nigeria, and on a visit in 2008, she saw how families struggled to afford their utility needs. With that reality in mind, she co-founded Uncharted Play to create fun products and services that address major societal issues.
#27 Trip Adler
Company: Scribd
Age: 29
Adler was a member of the same Harvard class as Mark Zuckerberg, but he waited until after graduation to launch his big idea. Scribd is a subscription service that provides unlimited access to a large digital library for a flat monthly fee. It spans about 40 million books and documents from 100 countries.
Before Adler struck gold with Scribd, he created 1-800-ASKTRIP, a call center where a caller could ask just about anything.
#26 Andy Pickens
Company: Jamplify
Age: 25
Andy Pickens and co-founder Moses Soyoola juggled a startup and a career at Goldman Sachs New York during Jamplify's first year.
Jamplify is a service that creates social campaigns for brands and turns their fans into effective advertisers. Fans are given a unique URL to promote a favorite artist, business, or initiative, and those who drive the most referrers over the course of two to three weeks win tiered prizes.
Pickens is a big fan of G. Love and Special Sauce, and would like DMX to record his voicemail message.
#25 Kellee Khalil
Company: Loverly
Age: 28
Kellee Khalil is a tech-obsessed vegetarian-foodie and Yogi. Her company Loverly is the first bridal search engine, helping brides find ideas, vendors, and products for their weddings. Her site curates information from 35 wedding bloggers as well as 1,800 vendors representing 200,000 products.
More than 30% of users access Loverly through mobile devices — the iPhone app was selected by Apple as one of the most prestigious New and Noteworthy apps nationwide, and an iPad app is in development.
#24 Sarah Paiji
Company: Snapette
Age: ~29
Sarah Paiji dropped out of Harvard Business School when she moved off her corporate Blackberry and onto her first iPhone, quickly realizing "there wasn't a moment to lose" before joining the ranks of female HBS grads who became startup sensations.
Snapette allows for virtual window-shopping: It's a mobile retail app for discovering fashion products in nearby stores. It sold to PriceGrabber in August, but will continue to operate as an independent company — marking one of the first successful exits for a fashion-related mobile technology startup to date.
#23 Josh Miller
Company: Branch
Age: 23
In 2011, Josh Miller moved into his senior year dorm room at Princeton and left a couple days later. He sent out to connect the world's conversationalists on one platform, Branch.
Branch hosts panel discussions between a limited number of participants, that anyone with a social media account, URL, or website can watch unfold online.
While in high school, Branch was named a CNN Hero Finalist in the "Young Wonder" category. He orchestrated a scholarship program with the purpose of alleviating racial tensions after the death of a friend, who was killed in a gang-related drive-by shooting.
#22 Amanda Peyton
Company: Grand St.
Age: ~30
Y Combinator alum Amanda Peyton and her team of tinkerers scour the Internet for offbeat electronics and gadgets, and showcase these products on the online store Grand St.
Before launching Grand St., Peyton co-founded the mobile messaging startup MessageParty and learned to speak Mandarin Chinese. As a sophomore at Northwestern, she accidentally bought an original Banksy work on the Internet.
#21 Shawn Oates
Company: SeamBLiSS
Age: ~25
[is there a better photo of him?]
Shawn Oates has a love for all things fashion. He created SeamBLiSS, an online marketplace where shoppers can connect and collaborate with designers and sewers for custom-fit and custom-designed apparel.
The Arkansas State alum graduated with a degree in engineering and spent all four years working as a part-time model. Oates enjoys sushi and football.
#20 Jamie Wong
Company: Vayable
Age: 26
Jamie Wong is a Y Combinator alum, former researcher of "The Daily Show with Jon Stewart," and founder of Vayable, a website that makes it easy to discover and book unique travel experiences.
Vayable stirred some buzz in Silicon Valley this month when it set up pop-up headquarters in Paris—where most of Vayable's users are based—for one month. Wong called it the best decision for her startup.
She speaks six languages: English, Spanish, Hebrew, Cantonese, and French.
#19 Nnena Ukuku
Company: Black Founders
Age: N/A
Nnena Ukuku is on a mission to close the gap in Silicon Valley for black and women entrepreneurs. This Southern transplant and practicing attorney helps startups use the law to give them full creative freedom.
Friends of Black Founders is a charitable organization that operates educational programs and conferences, and Black Founders Startup Ventures is a separate for-profit with a focus on startup financing.
Ukuku enjoys dancing tango, writing plays, cooking, and singing.
#18 Anthony Goldbloom
Company: Kaggle
Age: 30
Anthony Goldbloom is changing the way data-driven problems are solved. Kaggle hosts the world's largest community of data scientists, who compete with each other to solve complex data science problems and are rewarded with consulting roles on interesting projects.
This Aussie previously worked as an analyst at the Australian Treasury. Besides data mining, his interests include kitesurfing, mountain biking, and badminton.
#17 Ruzwana Bashir
Company: Peek
Age: 33
This travel junkie has navigated her way through 40 countries, and now helps others plan unforgettable experiences with her company. Peek works with vendors and travel experts to handpick the best activities for its curated travel itineraries.
A Harvard Business School Fulbright Scholar and former president of the Oxford Union, Bashir previously worked at Gilt Groupe, Art.sy, and Goldman Sachs.
#16 Ryan Rzepecki
Company: Social Bicycles
Age: ~34
Ryan Rzepecki is making Citi Bike smart. The city bike-sharing program Social Bicycles lets you reserve, rent, and lock bicycles via its website or smartphone app. GPS technology enables users to find the nearest available bike, and you don't have to return to a Social Bicycles-made hub when you're in a rush.
Rzepecki's Master's degree in urban planning and work experience at the New York City Department of Transportation in the Bike Planning group prepared him for the challenges of running a startup.
#15 Bryan Burkhart
Company: H.Bloom
Age: ~40
Bryan Burkhart wields some serious flower power. He started at software startup Callidus, helping it grow to $100 million in revenue and an IPO, and then went on to co-found H.Bloom, a subscription-based floral arrangement service.
This Wharton School grad is a contributor to The New York Times with a blog about team-building, talent development, and leadership.
#14 Kathryn Minshew
Company: The Muse
Age: 27
Her LinkedIn profile proudly declares, "I get things done" — and now, Kathryn Minshew is helping job-seeking professionals do the same. Her website The Muse helps more than 3 million users discover new career paths, find great companies through innovative hiring profiles, and get personalized job recommendations.
Previously Minshew worked on vaccine introduction in Rwanda and Malawi with the Clinton Health Access Initiative and before that, at the management consultancy McKinsey & Company.
#13 Olga Vidisheva
Company: Shoptiques
Age: 28
For almost three years Vidisheva, who emigrated from Russia to the U.S., had a dream of becoming a successful banker; she worked at Goldman Sachs around the clock, sometimes even sleeping on the floor of her cubicle.
But the former model was inspired to start her boutique-curated shopping site, Shoptiques, while on a trip to Paris in her post-Goldman days at Harvard Business School. Now she's hoping to access the $20 billion small retail market with the help of a very successful investment round.
#12 Zach Sims
Company: Codecademy
Age: ~23
Codecademy, which launched in August of 2011, was founded on the idea that anyone could learn to code—and that they should be able to do it for free.
Within its first 72 hours, 200,000 people began taking its lessons and teaching themselves basic JavaScript, and five months after launch Sims saw 1 million users. Even New York City Mayor Michael Bloomberg made it his New Year's resolution to learn to code on the site.
Sims was a political science major at Columbia before dropping out to start Codecademy.
#11 Julie Sygiel
Company: Dear Kate
Age: ~24
Sygiel's new underwear company "address[es] a big problem few women speak about," according to a Mashable interview with Sygiel. The underwear is leak- and stain-resistant, providing many women with peace of mind while wearing them.
Normally one would think that underwear like this could be hideous, but the Southern Belle has managed to make them look cute. The fabric used is a material she developed as a chemical engineering student at Brown University, and an idea was born. Sygiel started her company in Providence, R.I., and this year moved the operation to New York City.
#10 Travis Kalanick
Company: Uber
Age: 37
Uber is revolutionary for people who live in cities where public transportation is unreliable—simply ping the mobile app to summon a driver whenever you need one.
This concept helped the company grow incredibly rapidly, and this year it raised $35 billion. Yes, billion. With a "b." Private equity firm TPG purchased 775,092 shares at $114.03 a piece for a near $90 million investment, while Google Ventures and Benchmark made up much of the rest.
Uber has been coming up with a number of new, short-term marketing ploys as well—but ones that could easily be implemented for the long-term in the near future. Kalanick's team has done on-demand ice cream trucks this past summer, which delivered ice cream to those who hailed the truck on their phones; on-demand roses on Valentine's day; helicopter rides to the Hamptons during Fourth of July weekend; and on-demand barbecue in Texas.
#9 Ayah Bdeir
Company: littleBits
Age: ~31
Bdeir, who's been programming since she was 12, originally hails from Lebanon and Canada. She built littleBits in 2011, an award-winning database of electronics that's being called “LEGOs for the iPad generation.”
Recently named number 33 on Fast Company’s Most Creative People in Business for 2013, Bdeir hopes that her littleBits kits will serve as tools for creative people who want to build prototypes of real products.
The MIT alum was married just this month.
#8 Georg Petschnigg
Company: FiftyThree
Age: ~35
Petschnigg's app development company, FiftyThree, is the brain behind the creation of the award-winning drawing and graphic design iPad app, Paper. FiftyThree, which just recently raised $15 million in a Series A round from some of the most sought-after investors in the startup world, aims to become "the Adobe of the tablet and smartphone generation."
Petschnigg got his bachelor's at Columbia, his master's at Stanford, and speaks English, German, and French. He also plays the trumpet.
#7 Daniella Yacobovsky and Amy Jain
Company: BaubleBar
Age: Both 30
The two co-founders worked at the same investment bank after college, and later attended Harvard Business School together, where they conceived of the idea for BaubleBar after realizing that no one brand comes to mind when it comes to buying everyday jewelry.
BaubleBar uses a traditional e-commerce business model: They purchase jewelry at wholesale prices from manufacturers, then sell it for more online. Jain and Yacobovsky have seen a lot of success, even with individual sales—one customer has spent more on BaubleBar jewelry than some of the company's employees earn.
#6 Robert Reffkin
Company: Urban Compass
Age: ~33
When the former White House fellow isn't running his New York City apartment rental site Urban Compass, he's running 50 marathons across each of the 50 states to raise $1 million for charity. Reffkin was previously the Chief of Staff to the President and COO of Goldman Sachs, and also worked at McKinsey & Co.
Reffkin delves even further into his passion for philanthropy as a member on the boards of the Citizens Committee for NYC and Montefiore Hospital in the Bronx; he also served as founding chair of Bronx Success Academy 1 Charter School.
On top of all this, Reffkin is a new father, and makes plenty of time to spend with his three-month-old daughter.
#5 Rachel Brooks
Company: Citizen Made
Age: 26
Brooks got her start in fashion and advertising before making the switch to entrepreneurship and officially launching her custom sales software company, Citizen Made, in April.
Citizen Made helps mainly Chicago-based businesses build their online stores by making it easier for their customers to personalize, visualize, buy, and share products in different colors, styles, and designs. It gives Brooks the opportunity to continue to exercise her creativity on a day-to-day basis. Fun fact: She also knows how to make her own bowties.
#4 Chris Altchek
Company: Policy Mic
Age: 26
The Harvard grad, who'd always had a healthy appreciation for political and economic debate, followed his gut in 2011 and left his cushy job at Goldman Sachs to start his Millennial-run, politics-focused news site PolicyMic.
The team now has 16 staffers, but it started out with just two—Altchek and his co-founder, Jake Horowitz—who, in the company's early days, not only worked together, but lived together in a house they rented in Harlem.
#3 Kim Taylor
Company: Ranku
Age: 31
You may recognize Kim Taylor as one of the stars from Randi Zuckerberg's "Start-Ups: Silicon Valley" Bravo reality TV show. These days though, the former gymnast and NBA dancer is putting all of her energy into her new startup, Ranku.
The purpose of Ranku is to help non-profit universities with online degree programs get a leg up against for-profit ones while serving as a resource for people seeking more information about online degrees, Taylor told Business Insider in a recent interview. Though the startup is only a few months old, tech gurus like Mark Cuban are already putting their faith—and funds—in the company.
#2 Evan Spiegel
Company: Snapchat
Age: 23
The Stanford University grad started his photo messaging app while still a student, and continued to build the product—one of the top 10 downloaded from the App Store—through his graduation in 2012.
Spiegel, who serves on President Obama's Council on Technology and Media, still personally hires every new developer added to the growing team.
The company isn't currently generating revenue, but Spiegel recently raised a $60 million Series B round, and hopes to start generating revenue before the next funding round.
#1 Brit Morin
Company: Brit + Co.
Age: 27
Morin, who used to work for both Google and Apple, left to start her own company in 2011 and is now known as "Silicon Valley's Martha Stewart." The southern-born entrepreneur says her parents weren't very domestic growing up, and everything she knows is self-taught.
Brit + Co., Morin's online DIY e-commerce company, has VCs everywhere buzzing these days. aAs of June, the company raised a $6.3 million Series A round of financing from firms like Index Ventures, Lerer Ventures, and Cowboy Ventures. Marissa Mayer is also an investor in the startup.