Give me a summary of Dataphor based on this text

Context: Dataphor is an open-source truly-relational database management system and its accompanying user interface technologies, which together are designed to provide highly declarative software application development. The Dataphor Server has its own storage engine or it can be a virtual, or federated, DBMS, meaning that it can utilize other database engines for storage.

Dataphor has been praised for its adherence to relational principles, more closely so than any SQL product.

Answer: Dataphor is an open-source database management system that provides a declarative software application development that has been praised for its adherence to relational principles. The Dataphor Server has its own storage engine but it can also utilize other database engines for storage that are virtual or federated DBMS.