Online learning enthusiasts could get a windfall of federal money under a $2-billion grant program that the Obama Administration described on Thursday. But how big the windfall will be—if it comes at all—remains unclear.

One thing is for sure: The four-year program, designed to expand job training at community colleges, signals a major endorsement of the movement to freely share learning materials on the Internet.

That movement took hold a decade ago with MIT’s plan to publish free online syllabi, lecture notes, and other content from all of its courses. With this program, run by the Labor Department, parts of the federal government are now embracing MIT’s radical idea as official policy—dangling what could be an unprecedented amount of money for more open courses.

“With $500-million available this year, this is easily one of the largest federal investments in open educational resources in history,” U.S. Education Secretary Arne Duncan said in a statement e-mailed to The Chronicle. Mr. Duncan’s agency is working with the Labor Department on the program.

So what specific tech goodies might the government invest in with all that money? Official announcements from the Labor Department and White House were short on details. But here’s what we can glean from a close look at the 53-page document that lays out the grant guidelines: The Obama administration is encouraging the development of high-quality immersive online-learning environments. It suggests courses with simulations, with constant feedback, and with interactive software that can tailor instruction and tutoring to individual students. It likes courses that students can use to teach themselves.

And it demands open access to everything: “All online and technology-enabled courses must permit free public use and distribution, including the ability to re-use course modules, via an online repository for learning materials to be established by the federal government.”

In other words, if a community college in Washington State gets a grant to build an aerospace program for workforce training, it would have to deposit all its digital stuff in an online library. Anybody who wants to use it would be able to download the content, and they would have full legal rights to reuse, revise, remix, or redistribute it, explained Cable Green, director of eLearning and open education at the Washington State Board for Community & Technical Colleges. That’s because the government is requiring that all work supported by the grants be made available under what’s known as a “Creative Commons Attribution 3.0 License,” which Mr. Green described as “one of the most open content licenses that exists.”

Beth Noveck, a professor at New York Law School and former White House technology official, wrote that the openness requirement represented “a fundamental and laudable shift in how grants are made in government.”

If all of this discussion of openness and free online courses sounds familiar, it is. The Obama administration outlined a similar great course giveaway in 2009, a $500-million proposal influenced by work done in the Open Learning Initiative at Carnegie Mellon University. The online proposal was part of a $12-billion plan to improve community colleges, called the American Graduation Initiative, but that plan collapsed during negotiations over legislation to overhaul student aid and the nation’s health-care system.

The prospect that similar ideas could survive through this Labor Department program thrilled openness advocates like Mr. Green. To save students money on textbooks, his state is working on an ambitious program to develop low-cost, online instructional materials for community and technical colleges. The federal money could mean more choices of content that his colleges could review for adoption in their classes.

“That’s a windfall,” he said. “The sheer volume of openly licensed content is going to expand dramatically.”

How dramatically is unclear. Creative Commons fanned excitement online with a blog post headlined, “U.S. Department of Labor and Department of Education commit $2-billion to create open educational resources for community colleges and career training.” And Dave Cormier, a proponent of open education based at the University of Prince Edward Island, seized on that story to argue that the money “could end the textbook industry as we know it.”

But when The Chronicle forwarded the Creative Commons story to Sara Gast, a spokeswoman for the Education Department, she doused a little cold water on all the excitement. “The headline is inaccurate,” she said in an e-mail. “But at this point, as the solicitation phase is just beginning, we don’t know how much of the $2B (or even $500-million in the first year) will be spent on open educational resources.”

She added, “All of the intellectual property that is created as a result of the grants has to be shared as OERs, and it would be accurate to say that the money is available to fund open educational resources, but there is no guarantee all those funds—or even any of those funds—will be spent for that purpose. The applicants have to make their case that what they propose will help students finish college more reliably with market-ready skills, degrees and certificates. We think OERs will be an important part of that. But how much? We can’t say yet.”