From Askmonty.org

The Maria team can only promise to cover bugs in Maria or code that we have included in MariaDB. For bugs in MySQL, we can't give any guarantees. However, bugs in MySQL that directly affect Maria or are related to Maria are likely to be fixed or worked around by the Maria team.

The Maria development release policy follows the MySQL release criteria. In addition to this we have the following project commitments for the maturity stages:

The release policy for all Maria storage engine releases and MariaDB:

• All MariaDB releases should be free from bugs that can cause problem in 'normal' operation for most users.
• We aim for one release per month until the code is stable. This will include a source release and binary release for all machines in our build farm for which MariaDB passes all tests.
• When MariaDB becomes stable we will do few releases monthly, but later only when critical bugs have been found and fixed.
• The MariaDB release will include all changes from the main MySQL tree up to at least the latest stable build of MySQL.
• If we make a release with known critical bugs (for example, if there is a really nasty bug we want to fix at once and get the fix out, while we are fixing other bugs), they will be documented in the KNOWN_BUGS.txt file.

Commitment for Beta

• Maria/MariaDB is feature complete according to what is agreed among the Maria team captains for the release.
• No known serious bugs, except for those marked as feature requests.
• No bugs fixed since our last release that have caused notable code changes.

Commitment for RC/Gamma

• No known serious bugs, except for those marked as feature requests
• No bugs fixed since last release that caused a notable code changes.
• We believe the code is ready for general usage (based on bug inflow), but we want more testing before calling it stable

Commitment for GA/stable (and all releases after this)

• No known serious bugs, except for those marked as feature requests.
• No bugs fixed since last release that caused a notable code changes.
• We believe the code is ready for general usage (based on bug inflow).

In the rare case when there is a bug that can't be fixed in a specific release (either because it's a design bug or the bug fix is likely to cause other, possibly worse bugs), we will document it in the KNOWN_BUGS.txt file that comes with the MariaDB distribution. However, we will try to keep these kinds of open bugs at a minimum.