Starting with MySQL release 8.0.0, the source code is now commented using the Doxygen documentation generation tool.
This project is long overdue … it has been a very well-worn issue, or an ever recurring wish, for the last 10 years.
Well, not any more.
The results are available at the following location:
Of all the content available, my personal preference (yes, I am biased) is for the performance schema documentation:
For those who enjoy UML notations (a picture is worth a thousand words), the documentation includes some hand written diagrams:
Enjoy browsing !
Edit Oct 2019:
Updated URLs to point to the latest release.
Archived doc is available here: