EdX, the free not-for-profit online learning venture co-founded by Harvard and MIT, will be adding a third university to the mix after EdX announced the addition of the University of California, Berkeley on Tuesday.

UC Berkeley, ranked by US News & World Report as the best public school in the nation, will offer two courses—both from the computer science department—to supplement the five pre-existing offerings, two from Harvard and three from MIT.

"We are very excited that Berkeley is coming on board,” said Anant Agarwal, President of EdX. “We share with Berkeley a common vision for non-profit learning worldwide. We have seen grass roots energy at the Professor and leadership levels of all three universities.”

Berkeley will also serve as the inaugural chair of the soon-to-be-formed “X University” Consortium, while bringing with it open source technology developed in a variety of on-campus online ventures that should enhance the online experience.

EdX was launched in May after MIT and Harvard each pledged $30 million in support to the venture which promises to expand access to education by providing a forum for students to learn from world-class professors. The prototype course of EdX, MITx's 6.002x Circuits & Electronics, was offered in December.

More than 150,000 students registered online.

“The way I think of it is that to this generation, it is equivalent to what back in the old days the opening of the public library was,” said Marcello Pagano, Professor of Statistical Computing at the Harvard School of Public Health. “It’s allowing anyone with a computer to come to our library and access any book in the world.”

Pagano will be co-teaching PH207x: Health in Numbers: Quantitative Methods in Clinical & Public Health Research, one of the two HarvardX courses, in the fall.

EdX had planned to expand beyond the original two universities from the beginning, but the addition of Berkeley is noteworthy for coming just a week after a competing platform, Coursera, announced an expanded roster of 16 top-tier universities.

A number of Berkeley professors had been using Coursera, a for-profit venture founded by two Stanford professors, prior to the EdX announcement.

“All of our faculty in the end can do whatever they want to do,” said Robert J. Birgeneau, the Chancellor of UC Berkeley. "It's up to them whether or not they want to continue using Coursera."

Despite the potential conflicting interests Birgeneau pledged his support behind EdX.

“We are committed to excellence in online education with the dual goals of distributing higher education more broadly and enriching the quality of campus-based education,” Birgeneau announced in a statement. “We share the vision of MIT and Harvard leadership and believe that collaborating with the not-for-profit model of edX is the best way to do this."

CS50x: Introduction to Computer Science I will be the other HarvardX offering. Both HarvardX courses begin on October 15. The two Berkeley offerings, CS191.1x Software as a Service and CS188.1x Artificial Intelligence, are both higher level computer science courses.

For the time being all EdX courses will be offered for free. But as EdX expands and looks to become sustainable, one way in which revenue will be generated will be through the certificate of mastery program. In the prototype course, over 7,000 enrollees opted for the certificate.

“As far as the fee, we haven’t figured it out,” Agarwal said. “But it will be part of our sustainability model. It will be on the order of $100, similar to that of a textbook. All the courses will offer certificates in the fall for free, but beyond that we will have to reassess.”

—Staff writer Alexander Koenig can be reached at akoenig@college.harvard.edu.