Now, with video streaming tools, videoconferencing programs, and the ability to share and edit documents online, anyone with an Internet connection can gain access to college- and graduate-level education.
In recent years, universities have used the Web to post lectures online for users to watch at no cost. In 2006, Salman Khan created Khan Academy, a nonprofit education organization that posts YouTube "micro-lectures" on topics ranging from mathematics to art history.
[See how colleges have utilized YouTube.]
But still the public clamored for more organized online programs, notes Eren Bali, CEO and cofounder of Udemy, an online education provider.
"We realized that people are looking for structured content even though there are heaps of content available [online]," he says. "You need some guidance and a community."
For students interested in free online education programs, here are three that offer structured courses.
1. Coursera: Professors at Stanford University offered a series of free computer science courses online in fall 2011. Hundreds of thousands of students enrolled, far exceeding traditional enrollments, notes Andrew Ng, a cofounder of Coursera and a professor at Stanford who taught a machine learning course during the experiment.
"I normally teach a 400-student class," says Ng, who instructed more than 100,000 students through the online course. "To reach a comparable size audience, I'd have to teach my normal class for 250 years."
[Discover the growth and popularity of online education.]
Motivated by the experiment's success, Ng and Daphne Koller, a Stanford professor who also taught a free online course, founded Coursera, an online platform that offers structured courses from prestigious universities at no cost to students. The service—which features professors from Princeton University, University of Michigan, University of Pennsylvania, and Stanford—has topped a million enrollments since launching in March.
"Today's top universities offer an amazing education to a miniscule fraction of the population," Ng says. "We'd like to see a future where top schools are teaching not just thousands of students, but millions."
Within a course, video lectures are broken into segments with online quizzes to ensure students understand the material. Assignments are computer graded currently but, Koller notes, peer grading will soon be implemented for courses that may have more open-ended questions and answers.
Students can also engage in Q&A forums, where other users vote a question up or down based on its value and quality.
"I have checked into the discussion forums to see if people had the same questions as me and found that they almost always did," says Yoav Bergner, a Coursera user who is completing postdoctoral research at Massachusetts Institute of Technology. "There were really inspiring, high-level discussions happening from students all over the world."
Ng says the forums have made the ability to educate and engage thousands of students feasible.
"If you want to learn something, sitting at home watching YouTube videos is kind of a lonely experience," he notes. "Having a community of students working on the material together—that helps students learn."
2. Udacity: Former Stanford professor Sebastian Thrun cofounded this online learning community in January 2012 after also teaching a free online Stanford course in fall 2011 that enrolled roughly 160,000 students.
"That made me wake up and think about education in general and realize that we have a system that serves a small number of people, and it's very exclusive and very expensive and nonscalable," he says.
Udacity, which currently offers computer science courses, relies less on video lectures and enables students to do more work through online quizzes and exercises, Thrun notes.
Udacity also depends on a vibrant community of peer learners to ask and answer questions in the forums, he says. "In fact, there are many instances when a student's quality of answer to a question exceeds my own quality of answer."
While Udacity's goal is to educate as many people as possible, the organization also focuses on job placement. Working with companies such as Google and Facebook, Thrun notes that Udacity has been able to "place about a half dozen students into jobs."
[Find out more about learning for free with MOOCs.]
3. Udemy: Offering courses such as "How to Create an Awesome Demo Video for Your Business," Udemy has branded itself by offering many courses that would not typically be found on a college campus.
"You go to Udemy because there's a specific thing you want to learn," says Richard Komaiko, who took the demo video course to improve the visibility of his business, AttorneyFee.com, a site for comparing lawyer costs. "The type of stuff that can't be found in a real university—that's what Udemy excels at."
Founded in May 2010, Udemy provides anyone with an Internet connection the opportunity to teach or learn online, says cofounder Bali, who leveraged online resources while growing up in southeast Turkey.
While some courses charge a fee, Bali notes that the majority of classes are free—including "The Faculty Project" courses, which showcase content from university professors—and focus on providing marketable skills to users.
"You cannot expect to just go to college and have it convert to the best job opportunity," he notes. "You need more unique skills. You have to improve your credibility."
Searching for an online program? Get our complete rankings of Top Online Education Programs.