Starting next fall, 10 prominent universities will form a consortium called Semester Online, offering about 30 online courses to their students -- whose classes will be covered by their regular tuition -- and to students elsewhere who would have to apply and be accepted and pay tuition of more than $4,000 a course.

Semester Online will be operated through the educational platform 2U, formerly known as 2tor, and will simulate many aspects of a classroom: Students will be able to virtually raise their hands, break into smaller discussion groups and arrange and hold online study sessions.

The virtual classroom is a cross between a Google Plus hangout and the opening sequence of "The Brady Bunch," where each student has his or her own square, the equivalent of a classroom chair.

Unlike the increasingly popular massive open online courses, or MOOCs, which are free classes offered by universities such as Harvard, MIT and Stanford, Semester Online classes will be small -- and will offer credit.

"Now we can provide students with a course that mirrors our classroom experience," says Edward S. Macias, provost and executive vice chancellor for academic affairs at Washington University in St. Louis, one of the participants.

"It's going to be the most rigorous, live, for-credit online experience ever," said Chip Paucek, a co-founder of 2U.

For many of the participating schools, which include Duke, the University of North Carolina at Chapel Hill, the University of Notre Dame and Wake Forest, Semester Online offerings will be their first undergraduate for-credit online courses, and the first to offer credit to students from outside the universities.

One draw for the schools is the expansion in their course catalogs.

"No university can deliver the full range of courses that both might be interesting and useful and enlightening to our students. Imagine if you don't have a person who works on the Sahel region in Africa, but another school does," said Peter Lange, the provost of Duke.

Courses will be offered outside regular classroom hours, as late as 10 p.m., said Paucek.

While the cost of Semester Online will be included in tuition for students at the member schools, students outside the consortium will pay about $1,400 per credit hour, or $4,200 to $5,600 a course.

The consortium has not yet set admission standards for outside students.