The OpenLDAP project has announced that the 2.6 series of the server has entered the long-term support (LTS) phase. It is expected to remain supported for the next five years, but new releases should only contain fixes but no new features. New features will now be introduced in 2.7 releases, and the first release in that series is expected this fall.
The 2.5 release series is in its end-of-life phase. It will continue to receive fixes for critical issues for the next two years, but users should upgrade to the 2.6 or 2.7 series before it becomes unsupported.