The Idealists

Max Ventilla wants to revolutionize the archaic U.S. school system. "Schools are structurally resistant to change in the model we currently have," said Ventilla, 35. "You can think of [AltSchool] as a Montessori 2.0."

Instead of confining kids to K-8 grade levels, AltSchool is made up of "micro-communities," which means kids might be in the same class as someone several years older.

Ventilla, a former Google (GOOGL) employee, came up with the idea while considering schooling options for his daughter, who is now 4.

AltSchool has raised $105 million and attracted big name investors including Mark Zuckerberg and Priscilla Chan, Peter Thiel's Founders Fund and Andreessen Horowitz.

Four AltSchool locations in San Francisco have a combined 150 kids enrolled. Schools will open in Brooklyn, Palo Alto, and two more in San Francisco this fall.

"We hope to be a catalyst for the broader space to pull together the technical and innovation that are happening," said Ventilla. -- Sara Ashley O'Brien