Markedly Structured Text (MyST)
MyST is a rich and extensible flavor of Markdown meant for technical documentation and publishing. MyST documents are CommonMark compliant, as it is a superset of CommonMark Markdown.
The relationship between MyST, reStructuredText, and Sphinx
MyST is an attempt at combining the simplicity and readability of Markdown with the power and flexibility of reStructuredText and the Sphinx platform.
Sphinx is a documentation generation framework written in Python. It heavily-utilizes reStructuredText syntax, which is another markup language for writing documents. In particular, Sphinx defines two extension points that are extremely useful: in-line roles and block-level directives.
MyST markdown provides a markdown equivalent of the reStructuredText syntax, meaning that you can do anything in MyST that you can do with reStructuredText.