DECWindows is a GUI to an OpenVMS system. The DECwindows Motif software follows a client/server processing model, where the server is a single-shared process that performs operations at the request of many client processes.
In most client/server relationships, the client system is located on the desktop, while the server system resides across the network. With DECwindows Motif, as in all X Window System environments, the server system resides on the desktop and displays graphics onscreen.
The client is a process, such as a desktop application or X Window System utility, that issues X protocol requests. For example, in the DECwindows Motif environment, desktop applications (such as DECterm) and X Window System utilities (such as xlsfonts) are the clients that interact with the X display server. The client controls what appears on the display server system and generates the graphic interface with which the user interacts.
In the DECwindows architecture, as with most client/server processing models, the client and display server may reside on separate systems. These systems are connected to each other by a network transport that is essentially transparent to the user. DECwindows Motif supports the following transport mechanisms:
- Local (shared memory)
- Local Area Transport (LAT)
- TCP/IP using either the Internet Protocol Version 4 (IPv4) or Internet Protocol Version 6 (IPv6) host name and address format
The following components make up the DECwindows Motif client software:
- Desktop applications
- X Window System utilities
- Session management utilities
- Programming libraries: X Library (Xlib), X Toolkit Intrinsics (Xt), OSF/Motif toolkit (Xm), VSI Extensions to Motif (DXm), Inter-Client Exchange (ICE) and X Session Management (XSMP) Extensions
Integrity: per active socket.