An entrepreneur today announced the launch of OpenEd, an online catalog of more than 250,000 web-based educational videos, games, and exercises through a platform designed to sort and recommend materials based on their alignment to the Common Core State Standards. Each resource has been reviewed by a teacher in the appropriate subject area.

Almost all of the academic materials recommended on the site are free, and OpenEd itself is free to use.

Educators, parents, and students can search the site by keyword, subject, grade, and by any one of the 3,300 common core standards currently in place, as well as Next Generation Science Standards and National Geography Standards, among others. For instance, common-core standard 7.NS.3 is “solve real-world and mathematic problems involving the four operations with rational numbers,” and OpenEd recommends four resources for this standard.

OpenEd uses an algorithm-based recommendation engine, not unlike Amazon’s use of a similar technology to recommend products based on a customer’s previous choices. The OpenEd site generates recommendations of relevant videos and other resources for teachers creating lessons, or selecting materials for a course.

Technologist and serial entrepreneur Adam Blum and his wife, Lisa, have invested $500,000 in the Los Gatos, Calif.-based venture, which was inspired by their son’s ability to improve his grades, when he began struggling in science, from Cs and Ds to As and Bs, with the help of free, online educational videos.

“I sold my last company in 2011. My wife and I wanted to do something to give back,” Blum explained in a phone interview, referring to the sale of Rhomobile to Motorola.

Besides making this repository available to educators and students at no cost, the site features an open-application programming interface, or API, which means that any education technology provider, including assessment and adaptive learning companies, can access the source code to use the site’s recommendation engine. While existing learning management systems can use OpenEd at no cost, educators can use it alone to create their own courses, selecting materials aligned to specific standards, and receiving automated recommendations for others like it.

Blum and a team of a dozen people—including nine computer scientists—have been working full-time on what he called “the hard, computer-science algorithmic problem of aligning standards to resources,” and 99 percent of the recommendations are generated via that deep algorithmic software, he said.

Teachers were hired as subject matter experts to verify the standard alignments generated by the recommendation engine.

Blum said the closest competitors to his concept are WatchKnowLearn, Curriki, and OER Commons. Each of these catalogs about 50,000 open resources. “They all started about 10 years ago, as not-for-profits. In many ways, we’re second generation,” he explained.

Other sites that offer resources designed to judge the alignment of academic materials with the common core are PowerMyLearning, which is free, and Learning List, which is subscription-based, reviewing instructional materials that are both open-source and products sold by publishers.

Other organizations are attempting to help educators make sense of the academic resources marketed to schools. We recently reported on review sites that offer teachers suggestions for educational technology.

While Blum said his catalog will be “free forever,” OpenEd was organized as a C corporation, rather than a non-profit. “I’ve done several startups in Silicon Valley, so we could go almost indefinitely at our current run rate,” said Blum, estimating that this venture could be self-funded for 70 years. He is talking now to a venture capitalist who is also passionate about education, and expects to accept an investment in return for a small percentage of the company.

Blum is considering offering analytics, at a cost, to help teachers see how well students are learning from specific materials.

“When you talk to teachers about making it available as a subscriber service at $10 per month, no teacher or parent thought that was unreasonable,” he said. Adding that premium service at an affordable rate will add to the sustainability of OpenEd’s service.

“Ninety-nine percent of the resources we have today are free, because we really believe in open educational resources,” said Blum. However, at this year’s International Society for Technology in Education conference, representatives of companies selling content asked to be indexed, too. His company allowed them to do that, “as long as we felt it was high-value content at a reasonable price,” Blum said.