Become a sponsor to Allen Downey

I write books for people learning to program and to work with data, and through Green Tea Press I make them free to read online.

My books include Think Python, Think Stats, Think Bayes, Think DSP, Think Complexity, Modeling and Simulation in Python and The Little Book of Semaphores. Every chapter is a Jupyter notebook you can run in Colab, and the text is under a Creative Commons license. They are used in university courses around the world and by many more people learning on their own.

Your sponsorship pays for the work that keeps free books useful:

• keeping the notebooks running as Python and its libraries change
• fixing errors readers report
• hosting the books and their data
• new editions and new books

Any amount helps. A one-time contribution after a chapter that helped you is great. A monthly sponsorship, even a small one, helps me plan.

If you'd rather buy a book, the print editions are available from the publishers, and that helps too.

Thank you for reading, and for keeping the books free for the next person.