Rock (OMLx 4.3) is the workstation and server edition published by the OpenMandriva Association. Also for individual users that do not like change.
It would be the most stable and suitable for users that like things to stay as they are and just work. Package upgrades will be limited mostly to bug fixes, and security updates.
Rock repositories consist of a symbolic link to the latest stable version of OpenMandriva Lx. Currently Rock is linked to OMLx 4.3, however when OMLx 5.0 is released, Rock will automatically be switched to OMLx 5.0.
Any stable version will eventually reach EOL (End Of Life) after the new version is released and there will be no more updates of any kind.