We are currently working on this new version that will replace and improve upon the original, Flash-based version. What you can access here now is a draft version-in-progress, with much basic content and functionality in place, but still with some missing parts and assorted bugs.
We will replace it with the full and complete redesign as soon as possible. Meanwhile, enjoy this draft version, and thanks for your patience.
Revised and recoded (2019) by Emily Thompson and Ben Johnston.
Produced through the McGraw Center for Teaching and Learning
at Princeton University.