AIX ( Advanced Interactive eXecutive, pronounced ) is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms.

A beta test version of AIX 5L for IA-64 systems was released, but according to documents released in the SCO v. IBM lawsuit, less than forty licenses for the finished Monterey Unix were ever sold before the project was terminated in 2002.

* List of Unix systems

Their operating systems, called MCP ( Master Control Program — the name later borrowed by the screenwriters for Tron ), were programmed in ESPOL ( Executive Systems Programming Oriented Language, a minor extension of ALGOL ), and later in NEWP ( with further extensions to ALGOL ) almost a decade before Unix.

* Postfix – A fast, secure, easy-to-administer MTA for Linux / Unix systems

; CLISP: A bytecode-compiling implementation, portable and runs on a number of Unix and Unix-like systems ( including Mac OS X ), as well as Microsoft Windows and several other systems.

Cygwin consists of a library that implements the POSIX system call API in terms of Win32 system calls, a GNU development toolchain ( including GCC and GDB ) to allow software development, and a large number of application programs equivalent to those on Unix systems.

Cygwin permits installing inetd, syslogd, sshd, Apache, and other daemons as standard Windows services, allowing Microsoft Windows systems to emulate Unix and Linux servers.

Efforts to reconcile concepts that differ between Unix and Windows systems include:

Initial mount points can be configured in, which has a very similar format as on Unix systems, except that Windows paths appear in place of devices.

Unix file systems are usually case sensitive and allow user-level applications to create files whose names differ only in the case of characters.

Computer operating systems as far back as early Unix have included interactive calculator programs such as dc and hoc, and calculator functions are included in almost all PDA-type devices ( save a few dedicated address book and dictionary devices ).

The PDP-11 supported several operating systems, including Bell Labs ' new Unix operating system as well as DEC's DOS-11, RSX-11, IAS, RT-11, DSM-11, and RSTS / E.

Both RSTS and Unix were time-sharing systems available to educational institutions at little or no cost, and these PDP-11 systems were destined to be the " sandbox " for a rising generation of engineers and computer scientists.

* dm ( for Dungeon Master ), a program included in some versions of BSD Unix and operating systems derived from it, which could be used to restrict the playing of games on a computer to certain times of the day ( dm manual page from 4. 4BSD )

BIND was widely distributed, especially on Unix systems, and is the dominant DNS software in use on the Internet.

In large machines there were other disk operating systems, such as IBM's VM, DEC's RSTS / RT-11 / VMS / TOPS-10 / TWENEX, MIT's ITS / CTSS, Control Data's assorted NOS variants, Harris's Vulcan, Bell Labs ' Unix, and so on.

Two other groups contributed to the design of the language and developed implementations: Harlequin released a commercial IDE for Microsoft Windows and Carnegie Mellon University released an open source compiler for Unix systems.

* available on essentially all Unix systems ( and mandatory on systems conforming to the Single Unix Specification ).

The clone is available for download as part of the FreeDOS project, and runs on operating systems such as Linux or Unix as well as MS-DOS.

In late 1988 it was ported to C, which enabled it to spread rapidly to many Unix platforms upon its release in 1989.

Developers such as Maria Mariani, Soft-Art, Microlytics, Proximity, Circle Noetics, and Reference Software rushed OEM packages or end-user products into the rapidly expanding software market, primarily for the PC but also for Apple Macintosh, VAX, and Unix.

This program was available in DOS, Windows 3. x, OS / 2 2. 0 and SCO Unix versions, and claimed to transfer files more rapidly than Laplink at that time.

It saw use in some late-model Amiga machines and Amiga accelerator cards as well as some Atari ST clones and a Falcon accelerator board ( CT060 ), and very late models of the Alpha Microsystems multiuser computers before their migration to x86, but Apple Inc. and the Unix world had moved onto various RISC platforms by the time the ' 060 was available.

By that time, most services had moved to client / server-based computing systems, typically Unix for servers and various Mac, PC, and Unix flavors for clients.

The earliest versions were written on the Unix system at UC Santa Cruz and later coding moved, along with Michael Toy, to UC Berkeley.

It initially started in the production of analogue computers to control flight simulators, then moved to produce minicomputers (" R range "), departmental Unix Servers and microcomputers (" teleputers "), specialising in data capture, enterprise accounting for local government and videotex systems.

Netatalk was originally developed by the Research Systems Unix Group at the University of Michigan and moved to SourceForge in 2000.

After the URL contents were moved to the Unix host, they had to be moved down to the PC.

These are more compliant with Unix terminal standards and user interface conventions than the Cygwin console, but are less suited for running Windows console programs.

Cygwin's default package selection is fairly minimal, containing little more than the bash shell and the core file manipulation utilities expected of a Unix command line.

* ed, a more powerful Unix line editor with regular expressions.

* is a Unix binary utility that displays information about one or more ELF files.

More recent Unix or Unix like systems ( e. g., Linux or the various BSD systems ) use more secure password hashing algorithms such as PBKDF2, bcrypt and scrypt which have large salts and an adjustable cost or number of iterations.

typical Unix program that does exactly what it should and nothing more.

The term was popularized in the early 1980s, mainly to describe systems based on Unix, especially in contrast to the more entrenched mainframes and minicomputers in use at that time.

Consequently an IBM mainframe with Linux on zSeries is marketed as being more of an open system than commodity computers using closed-source Microsoft Windows — or even those using Unix, despite its open systems heritage.

Performance testing technology employs one or more PCs or Unix servers to act as injectors – each emulating the presence of numbers of users and each running an automated sequence of interactions ( recorded as a script, or as a series of scripts to emulate different types of user interaction ) with the host whose performance is being tested.

In particular, these University of Illinois students made two key changes to the Web browser, which hyper-boosted its appeal: they added graphics to what was otherwise boring text-based software, and, most importantly, they ported the software from so-called Unix computers that are popular only in technical and academic circles, to the Windows operating system, which is used on more than 80 percent of the computers in the world, especially personal and commercial computers.

As such, it could be considered a type of graphical user interface ( GUI ), albeit much more primitive than the later Unix, Windows and Macintosh based GUI IM software.

By the early 1990s, the major UNIX system vendors had begun to realize that the standards rivalries often termed as the Unix wars were causing all participants more harm than good, leaving the UNIX industry open to emerging competition from Microsoft.

Higher-end workstations still use more sophisticated CPUs such as the modern iterations of the Intel Xeon, AMD Opteron, IBM POWER, or Sun UltraSPARC CPUs, and typically run a variant of Unix, often allowing these machines to still focus on one area of expertise extensively.

As a creation of the mid-1970s, with no constraints to be compatible with earlier operating systems, VME is in many ways more modern in its architecture than today's Unix derivatives ( Unix was designed in the 1960s ) or Microsoft Windows ( which started as an operating system for single-user computers, and still betrays those origins ).

The Unix system had been written almost exclusively in C, so the C shell's first objective was a command language that was more stylistically consistent with the rest of the system.

Though commonly associated with the Unix shebang at the start of an interpreted script, the problem is more widespread.

Although Apollo systems were easy to use and administer, they became less cost-effective because the proprietary operating system made software more expensive than Unix software.

Richard P. Gabriel suggests that a key advantage of Unix was that it embodied a design philosophy he termed " worse is better ", in which simplicity of both the interface and the implementation are more important than any other attributes of the system — including correctness, consistency, and completeness.

" He apparently connected these ideas to those of Richard Stallman and saw related ideas that are important in the design philosophy of Unix, and more generally in the open-source movement, both of which were central to the development of Linux.

It can be argued, however, that there are already object-oriented concepts involved in the design of a more typical operating system such as Unix.

While a more traditional language like C does not support object orientation as fluidly as more recent languages, the notion of, for example, a file, stream, or device driver ( in Unix, each represented as a file descriptor ) can be considered a good example of object orientation: they are, after all, abstract data types, with various methods in the form of system calls, whose behavior varies based on the type of object, whose implementation details are hidden from the caller, and might even use inheritance in their underlying code.