The KOBV Portal is the regional library portal for Berlin and Brandenburg. It contains almost all the library holdings from the KOBV libraries in Berlin and Brandenburg (Status of the data).
The current version 3.1 includes the new facet Year which can be used after choosing a value from facet Years. It enables you to filter your hit list for a certain publishing year.
Furthermore you can now find the data from the EDOC server of the Humboldt-Universität zu Berlin in the KOBV Portal.
All other changes can be found in the release notes.
More detailed information about the portal can be found in the KOBV portal help.