P3M3® (The Portfolio, Programme, and Project Management Maturity Model) is a methodology owned and published by the Cabinet Office (ex OGC). It is a framework for evaluating the maturity and performance of assets of an organization.
PostgreSQL is a product, a commercial relational database. It is one of the most popular open source database (relational database systems).
P3O ® (Portfolio, Programme and Project Offices) is a methodology owned and published by the UK Cabinet Office (ex OGC). It is a set of principles, processes and techniques intended to facilitate the management of a project, its program and project management portfolio, which is aligned to correspond with other methodologies issued by the Cabinet Office - PRINCE2, MSP, and M_o_R.