This is the PostgreSQL adapter for Zope 2 and 3 based on psycopg2. It used to be in psycopg2 until the 2.4.x branch, but creating an external project allows for more specific development and maintenance. The package depends on psycopg2.
If you are a Zope user and want to contribute to this project maintenance, please contact the Psycopg mailing list.