Integrated Database Management System
IDMS was licensed to ICL in 1976 for porting to, and subsequent development on, their computers. It was implemented on the ICL 1900 Series (DME George 2, George 3, CME, TME), System 4, and ICL 2900 Series (later Series 39 Corporate Servers). The latest version runs on Series 39 OpenVME as IDMSX (IDMS extended).
[Was it a relational database?]