ORB Object Request Broker A software router, or object bus that allows software objects to communicate with each other, both locally and remotely.
CORBA Common Object Request Broker Architecture The Open Distributed Object standard sponsored by the Object Management Group, a consortium of over 700 companies in the software industry.
IDL Interface Definition Language CORBA's neutral language that allows component providers to specify the interface and structure of the objects they provide. The grammar is a subset of C++ with additional keywords to support distributed concepts.
IIOP Internet Inter-ORB Protocol The backbone protocol for CORBA, added as part of the 2.0 spec. TCP/IP with added CORBA-defined message exchanges. An ORB must either implement IIOP or provide a half-bridge to it to be 2.0 compliant.
SII Static Invocation Interface A CORBA interface that provides early binding of parameters, allowing the IDL compiler to check data-type correctness at compile time.
BOA Basic Object Adapter The primary interface that a CORBA 2.0 implementation uses to access ORB functions.
DCOM Distributed COM Microsoft's implementation of a distributed component architecture, built on COM.
COM Component Object Model Microsoft's specification describing the process of communicating through interfaces, acquiring access to interfaces through the QueryInterface method, determining pointer lifetime through reference counting, and re-using objects through aggregation.
OLE Object Linking and Embedding Microsoft's method for integrating the output from one program as data in another (for example, incorporating a drawing into a word-processing document).
OCX OLE Control eXtension Intended to replace Visual Basic Controls, these visual drag-and-drop components eventually evolved into ActiveX controls.
  ActiveX A leaner OLE for building binary software components that exist as either DLLs or executable files that can be run locally or across a network.

Netware Distribution Services Novell's way of providing a single, global, logical view of all network services and resources.
LDAP Lightweight Directory Access Protocol An open standard protocol for directory services. A subset of X.500, but can also be used with standalone and other kinds of directory servers. Recently positioned as an open standard for directory services on the Internet-a standard way for Internet client applications and Web servers to access online directories of people and information such as user names, email addresses, and telephone numbers.
X.500   A standard defining the protocols and information model for a global directory service independent of computing application and network platform. Based on a hierarchically distributed directory of named information that users can browse and search. A set of directory servers each holds a portion of the global directory information base. The servers coop erate to provide a directory service to user applications in a way similar to DNS-the user applications can connect to any directory server and issue queries to access information anywhere in the global directory. Basing a directory service on X.500 means access to data is secure and can be distributed or centralized.
RMI Remote Method Invocation Sun's Java-based architecture for providing distributed computing.