Imprivata, founded by David Ting, is helping business ditch user names and passwords. The company provides its enterprise-level customers with a variety of single sign-on methods--such as fingerprint analysis and smart identification cards--that employees can subsequently use to access various databases more quickly. Imprivata maintains that its authentication technology is secure, but could take a hit if any of its business customers were to experience a security breach. The security company's customers are primarily health care organizations, but Imprivata also works with banks, energy companies, and government organizations, and is exploring other highly regulated industries that it can service in the future. Note: employee count as of Dec. 31, 2015

Founded in 2007, Rubicon Project is one of the world’s largest advertising exchanges. The company helps websites and apps thrive by giving them tools and expertise to sell ads easily and safely. In addition, the world's leading agencies and brands rely on Rubicon Project’s technology to execute billions of advertising transactions each month. Rubicon Project is an independent, publicly traded company (NYSE:RUBI) headquartered in Los Angeles, California

Steven Boal founded Coupons.com to turn the tradition of scouring newspapers for coupons into a more high-tech process. Today, Coupons.com (now known as Quotient) acts as a digital bargain hunter for consumers, while simultaneously working with brands and retailers to provide them with insights into shoppers' habits. Boal told Inc. that the decision to rebrand Coupons.com as Quotient reflects a stronger focus on analytics, and was done to keep up with changing customer demands. "We've rebranded several times as our business has evolved," he says. Time will tell if the rebrand is a successful one. Note: employee count as of Dec. 31, 2015

Care.com founder Sheila Lirio Marcelo got the idea for an online marketplace for care providers after she struggled to find qualified professionals to take care of her aging parents. Today, consumers can search on Care.com for child, senior, pet, and home care services, while providers can create profiles and search for jobs. The company pledges to keep customers safe by giving them the option of requesting a background check on any care provider they wish to hire. Though its services are popular--Care.com currently has more than 10 million members--it has struggled to become profitable. But the company believes that its growing international business, particularly its Berlin-based subsidiary, Care.com Europe GmbH, will help it keep its competitive edge. Note: employee count as of Dec. 31, 2015

A picture might be worth a thousand words, but wearable-camera maker GoPro wants to ensure those stories get told. That's why, after a bumpy year, CEO Nick Woodman is emphasizing software. His San Mateo, California, company has recently introduced or improved several products to help customers edit videos on the fly, store them in the cloud, and, of course, make them in the first place. "GoPro got started in the packaging," says IFI analyst Larry Cady. "But now they've started patenting around more of the electronics, like image processing and network communications." --Victoria Finkle