Jupyter Book 2 is built upon the MyST-MD document engine, which serves a similar purpose to the Sphinx documentation engine used by Jupyter Book 1. However, MyST-MD is designed from the ground-up for technical and scientific writing, and provides some exciting features such as rabbit-hole links. Fundamentally, Jupyter Book 2 does not try to hide the fact that it is built on top of a document engine; MyST-MD is designed from the ground up to be good at technical writing, and the Jupyter Book team believe that its native configuration format and CLI are both powerful and easy-to-use. As such, Jupyter Book 2 builds on top of MyST-MD by using the same CLI and myst.yml configuration format.
Jupyter Book 2 is MyST-MD [...]; power users can use the MyST-MD CLI directly!
To minimize the complexity of integrating two separate software packages, the jupyter book binary shares the MyST-MD CLI, i.e. Jupyter Book 2 is MyST-MD (bundled with a default Jupyter Book configuration)! Whilst in future we may look to add new commands and options to the Jupyter Book CLI, the Jupyter Book team will always lean towards adding new features directly to MyST-MD; we firmly believe that the right choices for the MyST-MD CLI are the right choices for Jupyter Book. Consequently, power users can use the MyST-MD CLI directly! By keeping the distinction between Jupyter Book and MyST-MD as small as possible, we hope to ensure the mutual growth of both projects.