1. DONORSCHOOSE.ORG

For teaching government a thing or two about education reform. Most of us can agree that the U.S. school system is a mess: State education budgets are shrinking, while businesses' expectations for job preparedness are ever rising. Charles Best, founder and CEO of DonorsChoose.org, is trying to make sure teachers and students have the resources to do their part. The crowdfunding nonprofit has raised $225 million to help more than 175,000 teachers fund more than 400,000 projects, from securing school supplies for the semester to helping make field trips happen. Best, formerly a public-school history teacher in the Bronx, has managed to rein in some deep-pocketed donors and partners, including Sheryl Sandberg, Stephen Colbert, and Google, which is helping Best use his site in transformative ways, such as bringing AP STEM classes to more than 330 high schools and helping entrepreneurs market new educational tools directly to classrooms. Read more >>

2. INKLING

For rewriting the book on e-books. In the rush to embrace everything digital, many ed-tech companies forgot that people, not robots, are the end users. Enter Inkling, producer of lushly designed educational content for tablets and mobile phones. Last year, Inkling raised $16 million from Sequoia, among others, and signed deals with textbook giants Pearson and Elsevier to digitize its academic materials. It also opened its publishing platform, Habitat, to let publishers in-house create their own masterpieces, which founder Matt MacInnis says has helped net the company "eight figures" in revenue. True, there are other solid digitized textbooks, but with Inkling's multimedia features--live Q&As, how-to videos, interactive quizzes--its prom-queen level of popularity is well deserved.

3. KAPLAN

For testing and prepping students for the new era of education. The 75-year-old industry stalwart might have started as a test-prep company, but it continues to evolve to keep pace with students' changing learning habits--and the changing job market. It's wholly embracing and developing new tech-centric curriculums: Last year, it launched a pilot program at its university's School of Information Technology, which used the gamification platform Badgeville to boost participating students' grades by 9%, graduated the inaugural class of its Techstars-powered education startup accelerator, launched a boot camp for aspiring Ruby on Rails web developers, and--in its most strategic, and perhaps preemptive, move--acquired Grockit, the notable online test-prep service that recently logged on its one millionth user.

4. GENSPACE AND BIOCURIOUS

For letting the everyman explore the hidden corners of science. Community laboratories like Genspace, based in Brooklyn, New York, and BioCurious, based in Sunnyvale, California, are attracting biotech hackers interested in bridging the gulf that separates synthetic biology researchers from, well, everyone else. For a $100 monthly membership fee (which defrays the cost of running the lab), DIY geneticists can tinker with a vortexer, an ultrasonic bath, and gel electrophoresis to create cool experiments like glow-in-the-dark plants, wormlike creatures that crave butter, and robots that can do your pipetting for you. "It is science for the people," says Genspace cofounder and executive director Ellen Jorgensen.

5. LEARNZILLION

For understanding that teaching starts with teacher education. Founded in 2011 by a charter school chief and a McKinsey consultant, LearnZillion charges districts to supply teachers and students with five-minute mini-lessons based on the Common Core State Standards initiative--designed to align states' curriculums--and delivered by master teachers. Students can use LearnZillion to review class material, but equally as important, teachers can use it to get ideas for their own classes and to study videos to improve their teaching methods. The company has about 120,000 registered teachers (and adds 5,000 new teachers every week) and reaches about 1.4 million students. LearnZillion, a favorite of ed-tech enthusiast Bill Gates, has also formed alliances with Washington, D.C., and Syracuse, New York, public school systems.

6. KNEWTON

For using data to learn the way students learn. Adaptive learning is what good teachers have done since the dawn of time: When a student gets a question wrong, the teacher figures out where their knowledge failed and builds from that base. Now imagine that seemingly simple but complex process controlled by a series of computer algorithms, and you have the secret of Knewton, the former test-prep company that is fast achieving dominance in the digital learning space. Knewton has signed deals with textbook giants like Houghton Mifflin Harcourt and Macmillan to add an adaptive-learning layer to their content, and the company now boasts more than a million students from kindergarten through college as users of its technology. Unlike regular schooling, where learning can be limited by class size, the more Knewton users the better: When students use the platform, Knewton collects data on their progress and uses those analytics to weed out weaker questions in favor of stronger ones.

7. BEYOND 12

For stepping up to make sure every student gets a chance at higher ed. While almost everyone agrees that some form of post-secondary education is crucial, less than 10% of students from lower-income families obtain a college degree--compared with nearly 75% of middle- and upper-income kids. However, neither high schools nor colleges seem to be able to focus on exactly when and how lower-income students slip through the cracks. The San Francisco–based nonprofit Beyond 12 offers an online tool that helps high schools track what happens to their students once they doff their mortarboards, while also providing colleges a tool to help retain vulnerable students who are trying to beat the odds.

8. NOVA LABS

For nurturing and empowering a budding generation of scientists. Once home to fans of famed astronomer Carl Sagan, Nova Labs is now the go-to site for a nerd herd of thousands of U.S. high school students. With funding from NASA and Lockheed Martin--and under the watchful eye of education director and astrophysicist Rachel Connolly--Nova Labs is mixing fascinating narratives with big data to create a new kind of educational tool. The website, which is produced by PBS, allows curious minds to tinker, compete, and collaborate with the same data professional researchers use, to, say, build robots or track tropical storms. Nova wants to make sure this new generation of scientists is ready to take on the world. "Big data is fundamentally changing the way scientists do research," says Connolly.

9. TWITTER

For unleashing its engineering expertise to hack together a next-gen engineering school. While the hype grows around massive open online courses (MOOCs), Twitter University may be the tech innovation that really breaks higher education wide open. Last year, Twitter acquired Marakana, an open-source technical training company, to help keep their engineers at the top of their game--and perhaps more crucially, to find an efficient way to get their master engineers to amp up the skill level of recruits. If it works, imagine Twitter University (or Facebook or Google University) forming partnerships with community college–goers to create skilled workers, ready and able to do the job on Day One. Read more >>

10. KNOWRE

For deploying a data-centric learning platform that even a kid could use. Adaptive-learning tools can be intimidating for younger students. But KnowRe has developed a mathematics app that uses a fun, achievement-based, gamified interface to figure out what skills middle schoolers need to master algebra, then uses adaptive technology to tailor lessons, practices, and quizzes to make sure those gaps get filled in. While KnowRe is in its early stages, it has shown significant promise, with major buzz in the ed-tech industry: It was the winner of Google's Global K-Startup competition and has already amassed data and feedback from more than 11,000 beta users--including students and teachers from 34 pilot schools across the United States.