The document is a complete user manual for the object-oriented database management system ODRA (Object Database for Rapid Application development), including its Virtual Repository Management System (VRMS). VRMS allows for virtual integration of distributed, heterogeneous, redundant and fragmented data and service resources into a centralized, homogeneous, non-redundant and non-fragmented whole. The specification includes installation and administration manual, general architecture of the software, integrated development environment, description of an object-oriented data model, specification of database query and programming language SBQL (Stack-Based Query Language), virtual updateable views, sessions and transactions, a client-server protocol, and various front end and back end interoperability facilities implemented for ODRA.