This post is adapted from the QS Top Grad School Guide 2014/15. For the full version, download your free copy and turn to page 50.MOOC (massive open online course) is among the latest additions to the Oxford English Dictionary, and MOOCs have proven that despite some hiccoughs and skepticism, they are not going anywhere. As their prominence continues to grow and universities continue to improve the content and student support provided, there are plenty of reasons to enrol in a free online course. Here are seven…1. Join an online community over 10 million students strong.Between them, the three biggest MOOC platforms on the web – Coursera, EdX and Udacity – provide almost 700 online education courses to over 8.5 million students from more than 225 countries and territories. And that’s just the top three! Other popular MOOC platforms include Iversity, Open Learning, Alison, Udemy, Canvas Networks, FutureLearn, NovoEd, CourseSites, Miriada X and Open2Study.Many prominent universities are continuing to board the MOOC bandwagon, compiling materials from on-campus programs in order to expand their reach, promote their programs and, as an aside, to advance societal knowledge. Boston University in the US is one such latecomer to the party, having launched its first five MOOCs on EdX over the past year, while Hong Kong’s HKUST has become one of the first universities to offer degree credit for a MOOC, in this case a Coursera-hosted course on ‘The Science of Gastronomy’.2. Get a head start in your specialization.As a grad school applicant or prospective undergraduate, no doubt you’re pretty keen to get a look at the material you’ll be covering over the next few years. By seeking out MOOCs and other free online courses in your field, you’ll be able to get ahead of your fellow applicants or classmates (not that it’s a competition…) by expanding your learning and brushing up on existing knowledge way ahead of the start of term.Whether it’s an introductory course or a more specialized topic reserved for those already knowledgeable about the subject area, taking a MOOC ahead of enrolling in a full university course is a good way to get to know more about the various specializations in your field and to discover new potential vocations and interests. It may also help you to convince admissions staff of your dedication and passion for the subject.3. Learn alongside a diverse group of professionals and students.According to Coursera data, 75% of MOOC students hold at least a bachelor’s degree, 73% of users are in full-time employment and the average age of users is between 25 and 35. Many are seeking professional development, while some are looking to brush up on their existing knowledge.While this picture of the average MOOC-taker may leave a bitter taste in the mouths of those who championed free online courses as a way of extending access to higher education, it also shows just how seriously MOOCs are being taken by those who have already gained official qualifications, but choose to continue to study in their own time.Meanwhile, it seems that inclusivity is on the up, albeit at a slower pace than the overall course growth rate. Recent statistics show that 40% of all MOOC students on Coursera are from developing countries, with figures set to get better still as institutions and policy makers from around the world continue to discuss the many possibilities of online education courses.4. From computer science to renaissance poetry – study anything!Think of anything you’d like to learn about – be that biotechnology, modern mysticism or even Google – and chances are you’ll be able to find a relevant MOOC. Some free online courses are introductory, for learners wanting to dip their toes in unknown waters, and some are more complex, offering materials that are studied as part of real university courses, at both undergraduate and master’s level.Whereas once, computing and programming courses dominated the MOOC market, now humanities offerings are leading the way. According to Edsurge data, 20% of MOOCs today are in the humanities, 16% are in computer science and programming, 15% are in business and management, 11% in science and another 11% in health and medicine. Education and teaching, mathematics and statistics, engineering and social sciences all make up over 5% of MOOC offerings on the web respectively.5. Follow in the footsteps of Bill Gates.Billionaire Bill Gates, co-founder of Microsoft and one of the most famous university dropouts in history, makes no secret of the fact he’s partial to online learning. Most recently Gates undertook a MOOC in oceanography, telling The Chronicle, “It\u0027s kind of ironic that I\u0027m a dropout. I love college courses probably as much as anyone around.”With this, Gates gives a valuable reminder that online education courses, and all higher education programs for that matter, only help those who are passionate and genuinely want to learn. The freedom provided by MOOCs in particular means that users are allowed to test out as many courses as they like, and are able to learn at their own pace and in their own time.6. Interact in real-time with real people.With the rise of free online courses, the importance of providing a community for online learning has become of utmost importance across all MOOC platforms. Forums, peer review and real-time discussion during video lectures have all played a key part in making online education courses more interactive and user-friendly. If MOOC students feel they’re learning alongside peers, they’re more likely to return to complete the course.Julia Stiglitz, director of business development and strategic partnerships at Coursera, says the average response time for a post on Coursera’s forums stands at only 22 minutes. That’s even quicker than emailing a lecturer as a paying student!FutureLearn, a MOOC platform developed by academics from the Open University in the UK, is one such platform to emphasize the importance of peer learning, community and interaction. “On every page, every video, every article we integrate the discussion right alongside the content,” Simon Nelson, head of FutureLearn told The Guardian. “You can click a button, even in the middle of a video, and make a comment, ask a question or answer one.”7. Be a part of something global.Between the months of February and April this year, 697 new MOOCs came onto the global market, bringing the total up from 1,533 to a staggering 2,230.While the US is by far the most MOOC-active country, with 38.5% of Coursera students coming from the US, a number of developing countries can be seen among the top countries for MOOC student population. Brazil makes up 5.8% of Coursera enrolments, while India provides 5.3% and China 4.1%, all ahead of percentages of users from the UK (4%), Canada (4.1%), Russia (2.4%), Germany (1.7%), Spain (1.6%) and Australia (1.6%). Emerging economies such as Colombia, Mexico and Thailand are also among the top 20 countries, each hosting more than 1% of all Coursera students.Nor is it solely English-language courses that are growing. Of the 742 MOOCs on offer in Europe, Spain is the biggest provider with 253 MOOCs – way ahead of the UK’s 170 offerings. Of these MOOCs, the majority are hosted on Spanish-speaking MOOC platforms such as Miriada X, UNX and UNED COMA. Meanwhile Arabic and Chinese MOOCs saw the globe’s quickest growth rate in 2014.For the full version of this post, and more useful resources, download the QS Top Grad School Guide 2014/15 (free to download; site registration required).