(1) See
IP Multimedia Subsystem.
(2) (IMs) Instant messages. See
instant messaging.
(3) (
Information
Management
System) An early IBM hierarchical DBMS for IBM mainframes. IMS was widely implemented throughout the 1970s under MVS and continues to be used under z/OS. IMS/DB (IMS/DataBase) is the back end database part, and either IMS/TM (IMS/Transaction Manager) or CICS provides the front end online interaction.
IMS/TM, formerly IMS/DC (IMS/Data Communications), runs each transaction in its own address space and allows for more precise tuning than CICS, which runs all transactions in a region. IMS/TM is also used to access DB2 databases, and Java applications can access IMS databases. See
CICS.