Polyhedra is an in-memory database management system. It uses an Object-Relational data model, but is more strongly tied to object-oriented storage.
Custom API SQL
Relational Object-Oriented
In-Memory
http://www.polyhedra.com
Polyhedra PLC
GB
1994
Commercial
C++
AIX, BSD, HP-UX, Linux, Solaris, Windows
Proprietary