ClearPath IX Systems Installation and Configuration Guide

WWW
X
X.400
X.500
X/Open
See World Wide Web.
Glossary
A standard for electronic mail developed by the International Organization for
Standardization (ISO). Products implementing the X.400 standard provide a mail backbone
across which users can send e-mail, faxes, images, and EDI documents. See also message
store, message transfer agent (MTA), and remote user agent (RUA).
A standard for global directory services developed by the International Organization for
Standardization (ISO). The X.500 standard defines protocols and interfaces that enable
client applications to read and update directory databases on global directory servers. See
also directory service agent (DSA) and directory user agent (DUA).
An international nonprofit consortium dedicated to the advancement of open systems. Its
primary activities include defining standards and branding products to ensure
interoperability between the products of different vendors.
X/Open Distributed Transaction Processing (DTP) model
The distributed transaction processing model specified in standards developed by the
X/Open Company, Ltd. The TransIT Open/OLTP architecture is based on these standards.
The model defines four components of a DTP system. Application programs (AP) define
the boundaries of transactions and perform the actions that make up the transaction
(typically database updates). Resource managers (RM), such as database management
systems, provide access to shared resources. Communication resource managers (CRM)
allow application programs to communicate with each other. A transaction manager (TM)
assigns unique identifiers (XID) to transactions, monitors the progress of transactions, and
handles transaction completion or recovery. See also distributed transaction processing
(DTP), global transaction.
X terminal
A terminal that provides X Window Access for Single Point Operations. For SPO/HMP
Console, an LT501 X terminal provides this capability.
X Window Access
An SVR4-based GUI window environment that enables a user to perform various functions
in multiple windows on a single display screen.
3GL
4GL
See third-generation language.
See fourth-generation language.
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