Technical data

An open system allows the OpenVMS operating system, whether powered by
Alpha or VAX, to interoperate efficiently with Compaq Tru64 UNIX and with
other vendors’ operating systems, particularly with Windows NT and other UNIX
operating systems.
2.1.2 Understanding the Middleware Concept
Implementing open systems means using the right middleware between the
operating system and the hardware platform and applications. Consistent
middleware affords interoperability and portability when and where it is needed.
An open systems strategy involves a consistent middleware approach that is
based on standards and is embodied in layered software and in individual
operating systems, such as OpenVMS and UNIX. Compaq DCE is an example
of middleware, with standard interfaces supported on both OpenVMS and
UNIX. Compaq DCE, or Distributed Computing Environment, is an architecture
of standard programming interfaces, conventions, and server functions that
transparently distributes applications across heterogeneous networks.
As shown in Figure 2-1, OpenVMS and UNIX interoperate efficiently, especially
in areas that are common to both platforms: windowing interface, standard
POSIX and DCE programming interfaces, compilers, networking products, and
applications.
Figure 2–1: Comparison of OpenVMS and UNIX
DIGITAL Command Language
OpenVMS Mail
EDT, TPU editors
OpenVMS System
Management Utilities
DECnet Networking Utilities
OpenVMS System Services
Run-Time Libraries
OpenVMS RMS
DECset Source Control
OpenVMS Debugger
UNIX Commands and Shells
UNIX Mail Utilities
vi, ed, emacs, ex editors
UNIX System
Management Utilities
UNIX Networking Utilities
UNIX Libraries
RCS/SCCS
Ladybug, DEC FUSE
AdvFS and
other file systems
CDE Windows Interface
World Wide Web Browsers
Common Applications
TCP/IP Networking
Common Compilers
DCE
VM-0896A-AI
2.2 File Compatibility
The Network File System, or (NFS) provides a standard for the exchange of data
between machines running different operating systems. NFS enables users to
2–2 Understanding OpenVMS and UNIX Implementations