Phil Soran, one of Minnesota’s most successful technology entrepreneurs of the past 20 years, and Jim Leslie, another veteran technology CEO, thought they had retired.

But their interest in education and philanthropy has put the fifty-somethings back in business.

Soran and Leslie have raised a whopping $17 million — a huge amount for an initial round of equity seed capital from individuals for a Minnesota firm — to finance the growth of start-up, a University of Minnesota online video-communication technology that Vidku has acquired.

“I built this for my classroom and it just spread,” said Charlie Miller, one of three co-founders and an associate professor in the university’s College of Education and Human Development. “We didn’t spend a dollar on marketing and sales. And we had a third of the college on it.”

Miller, 35, who is also director of the college’s learning-technology laboratory, will soon resign from the faculty to join Vidku as an executive.

Vidku is based on “Flipgrid,” a software codeveloped by Miller. It has found fans in education, business and elsewhere as the fledgling company tested interest over the past year.

Soran and Leslie were invited to look into the technology in 2014 by Jean Quam, dean of the College of Education.

“Flipgrid is a platform that allows individuals, at their convenience, to engage in rich, video-based dialogues with others organized around topics and questions,” said Soran, who is executive chairman of Vidku. “Charlie is a Silicon Valley-class technology talent and a college professor who can present.”

A number of schools, businesses and even the U.S. Coast Guard, which is using it to field-test language proficiency, are at least testing the Vidku system. A church pastor uses it to pose questions to congregants, who use Flipgrid to respond to other members of their congregation with a short video.

The entrepreneurs acquired the Flipgrid technology from the College of Education for $6.75 million and a 4 percent equity stake in the company.

“This arrangement advances the university’s commitment to create new knowledge, invent new products and to translate our research to practical uses by partnering with industry and entrepreneurs,” Ryan Warren, chief of operations for the education college, said in an e-mail.

Leslie sought to distinguish the Flipgrid technology by comparing it with YouTube.

“YouTube is about broadcasting a point of view or experience,” said Leslie, CEO of Vidku. “Flipgrid is about creating a video-based dialogue around a topic.”

What was designed as an education tool to solicit thinking from “front-row to back-row” students is proving to have broader applications.

Vidku has 15 employees, including several university teaching assistants and graduate assistants. The company, armed with expansion capital, is hiring software professionals and plans to move from leased space at the university to the downtown area.

The $17 million raised is huge for an initial round of “angel” seed capital from affluent individuals who often raise a few million at most.

The principals have successful track records.

Soran, 58, who started as a middle school math teacher before joining IBM as a trainee, is one of the founders of Xiotech and the former CEO of Compellent. He took it public and sold to Dell for $800 million in 2011. Soran spent the past couple of years exploring and contributing to urban public, private and charter schools.

Leslie, 54, sold his Eden Prairie-based Midwave Corp. for $17.6 million to data center builder and systems integrator Datalink in 2011 and remained there until 2013. He and his wife underwrite scholarships for disadvantaged students at the university.