Have you always wanted to learn Chinese, jazz piano, or a programming language? Maybe you just want to brush up on world history or figure out how to finance that company you’ve been wanting to start for years. Now is the time to do it for free. Universities around the world—including Ivy League schools like Harvard University, Princeton University, and Columbia University—have recently launched hundreds of free online courses, according to Dhawal Shah, the founder of the online course search engine and review site Class Central.

Shah has been keeping track of these Massive Open Online Courses (MOOCs) on Class Central since 2011, when MOOCs were first starting to emerge as a trend. (The New York Times called 2012 "The Year of the MOOC.") Since then, the free course landscape has grown exponentially. “In the past seven years or so, over 800 universities have created around 10,000 of these MOOCs,” he writes on freeCodeCamp’s Medium page. In the last four months alone, 190 universities have made about 600 online courses available online for free.

The courses listed on Class Central are offered through different MOOC providers, like edX and Coursera. When you click through to the class you’ll be prompted to sign up for a membership with the individual website. (For tips on how to access Coursera’s free content, check out Shah’s guide.) Most of the courses are self-paced and can take anywhere from three weeks to several months to complete.

Although the classes are free, you might have to pay for some content, like graded assignments. And if you want to receive a verified certificate proving you've completed the course, you’ll have to pay for it. On edX, for instance, these tend to go for $90-$100. Still, it’s significantly cheaper than attending the class in-person.

Many of the newly released MOOCs cover your standard subjects—think computer science, math, and science—but there are a few oddballs, too. Yale, for instance, created a free online version of its popular happiness course—“Psychology and the Good Life”—in April 2017. Princeton University offers “HOPE: Human Odyssey to Political Existentialism,” which is designed to explore life’s unanswerable questions, like “Why breathe? Why breed? Why bleed?” You can also take a Harvard University class on 18th-century opera or a class on the “Power of Podcasting for Storytelling” from the University of Wollongong in Australia.

Here are 10 other courses we think look fascinating:

1. "Pixel Art for Video Games" from Michigan State University
2. "Toledo: Deciphering Secrets of Medieval Spain" from the University of Colorado system
3. "The Presidency and the Shape of the Supreme Court" from Trinity College in Connecticut
4. "The Health Effects of Climate Change" from Harvard University
5. "Backyard Meteorology: The Science of Weather" from Harvard University
6. "Introduction to Linguistics" from the University of Birmingham in the UK
7. "John Milton: Paradise Lost" from Dartmouth College
8. "Mind of the Universe—Robots in Society: Blessing or Curse?" from Delft University of Technology in the Netherlands
9. "The Book of Kells: Exploring an Irish Medieval Masterpiece" from Trinity College Dublin
10. "Mindfulness: What It Is, Where It Comes From, and How to Practice It" from Naropa University in Colorado

For the full course list, check out Shah’s article on Medium.