The MySQL Lifecycle Policy determines which versions
are actively supported, and for which platforms such support
The basic principle is that old versions are supported for a quite long, but definitely limited period, once they have been replaced by a newer GA version. For example, since the introduction of this policy, MySQL 3.23 and 4.0 have been retired.
The policy contains also provisions for a different kind of End of Life dismissal. When support for certain platforms has been discontinued by their vendors, of the platform is not widely used, …