OpenStep
Encyclopedia
OpenStep was an object-oriented application programming interface
(API) specification for an object-oriented operating system
that used a non-NeXTSTEP
operating system as its core, principally developed by NeXT
with Sun Microsystems
. OPENSTEP (all capitalized) was a specific implementation of the OpenStep API developed by NeXT. While originally built on a Mach-based Unix
(such as the core of NeXTSTEP
), versions of OpenStep were available for Solaris and Windows NT
as well. The software libraries that shipped with OPENSTEP are a superset of the original OpenStep specification.
and Sun Microsystems
, allowing this cut-down version of NeXT's NeXTSTEP
operating system
object layers to be run on Sun's Solaris operating system (more specifically, Solaris on SPARC
-based hardware). Most of the OpenStep effort was to strip away those portions of NeXTSTEP that depended on Mach
or NeXT-specific hardware being present. This resulted in a smaller system that consisted primarily of Display PostScript
, the Objective-C
runtime and compilers, and the majority of the NeXTSTEP Objective-C libraries. Not included was the basic operating system, or the display system.
The first draft of the API was published by NeXT in summer 1994. Later that year they released an OpenStep compliant version of their flagship operating system NeXTSTEP
, rebranded as OPENSTEP and supported on several of their platforms as well as Sun SPARC systems. The official OpenStep API, published in September 1994, was the first to split the API between Foundation and Application Kit and the first to use the "NS" prefix. Early versions of NeXTSTEP used an "NX" prefix and contained only the Application Kit, relying on standard Unix libc types for low-level data structures. OPENSTEP remained NeXT's primary operating system product until they were purchased by Apple Computer
in 1996. OPENSTEP was then combined with technologies from the existing Mac OS
to produce Mac OS X
.
Sun originally adopted the OpenStep environment with the intent of complementing Sun's CORBA
-compliant object system, Solaris NEO
(formerly known as Project DOE), by providing an object-oriented user interface toolkit to complement the object-oriented CORBA plumbing. The port involved integrating the OpenStep AppKit with the Display PostScript layer of the Sun X11 server, making the AppKit tolerant of multi-threaded code (as Project DOE was inherently heavily multi-threaded), implementing a Solaris daemon to simulate the behavior of Mach ports, extending the SunPro C++ compiler to support Objective-C
using NeXT's ObjC runtime, writing an X11 window manager
to implement the NeXTSTEP look and feel as much as possible, and integrating the NeXT development tools, such as Project Manager and Interface Builder, with the SunPro compiler. In order to provide a complete end-user environment, Sun also ported the NeXTSTEP-3.3 versions of several end-user applications, including Mail.app, Preview.app, Edit.app, Workspace Manager, and the dock.
The OpenStep and CORBA parts of the products were later split, and NEO was released in late 1995 without the OpenStep environment. In March 1996, Sun announced Joe, a product to integrate NEO with Java
. Sun shipped a beta release of the OpenStep environment for Solaris on July 22, 1996, and made it freely available for download in August 1996 for non-commercial use, and for sale in September 1996. OpenStep/Solaris only shipped for the SPARC architecture.
The API specification itself is composed of the two main sets of object-oriented classes: the GUI
and graphics front-end known as the Application Kit
, and the aforementioned Foundation Kit.
However, OpenStep also specified the use of Display PostScript, a versatile and powerful PostScript
-based method of drawing windows and graphics on screen. NeXT, with its devotion to implementing object-oriented solutions, supplied pswraps for interfacing C code to Display PostScript. pswraps acted in an encapsulative way and was somewhat object oriented. The Application Kit, Foundation, and Display PostScript comprise the three key technologies in the OpenStep specification; however, Display PostScript was featured in older NeXT technologies, such as NeXTSTEP.
on practically any operating system. The idea was to use OpenStep code as a basis for network-wide applications running across different platforms, as opposed to using CORBA
or some other system.
Primary among these packages was Portable Distributed Objects
(PDO). PDO was essentially an even more "stripped down" version of OpenStep containing only the Foundation Kit technologies, combined with new libraries to provide remote invocation with very little code. Unlike OpenStep, which defined an operating system that applications would run in, under PDO the libraries were compiled into the application itself, creating a stand-alone "native" application for a particular platform. PDO was small enough to be easily portable, and versions were released for all major server vendors.
PDO became somewhat infamous in the mid-1990s when NeXT staff took to writing in solutions to various CORBA magazine articles in a few lines of code, whereas the original article would fill several pages. Even though using PDO required the installation of a considerable amount of supporting code (Objective-C and the libraries), PDO applications were nevertheless considerably smaller than similar CORBA solutions, typically about one-half to one-third the size.
The similar D'OLE provided the same types of services, but presented the resulting objects as DCOM
objects, with the goal of allowing programmers to create DCOM services running on high-powered platforms, called from Microsoft Windows
applications. For instance one could develop a high-powered financial modeling application using D'OLE, and then call it directly from within Microsoft Excel
. When D'OLE was first released, OLE by itself only communicated between applications running on a single machine. PDO enabled NeXT to demonstrate Excel talking to other Microsoft applications across a network before Microsoft themselves were able to implement this functionality.
Another package developed on OpenStep was Enterprise Objects Framework
(EOF), a tremendously powerful (for the time) object-relational mapping
product. EOF became very popular in the enterprise market, notably in the financial sector where OPENSTEP caused something of a minor revolution.
, a sophisticated Mach-UNIX based operating system that originally ran only on NeXT's Motorola 68k-based workstations and that was then ported to run on 32-bit Intel x86
-based "IBM-compatible" personal computers
, PA-RISC
-based workstations from Hewlett-Packard
, and SPARC
-based workstations from Sun Microsystems
.
NeXT completed an implementation of OpenStep on their existing Mach-based OS and called it OPENSTEP for Mach 4.0, 4.1 and 4.2. It was, for all intents, NeXTSTEP 4.0, and still retained flagship NeXTSTEP technologies (such as DPS
, UNIX underpinnings, user interface characteristics like the Dock
and Shelf
, and so on), and retained the classic NeXTSTEP user interface and styles. OPENSTEP for Mach was further improved, in comparison to NeXTSTEP 3.3, with vastly improved driver support – however the environment to actually write drivers was changed with the introduction of the object-oriented DriverKit.
OPENSTEP for Mach supported Intel x86-based PC's, Sun's SPARC workstations, and NeXT's own 68k-based architectures, while the HP PA-RISC version was dropped. These versions continued to run on the underlying Mach-based OS used in NeXTSTEP. OPENSTEP for Mach became NeXT's primary OS from 1995 on, and was used mainly on the Intel platform. In addition to being a complete OpenStep implementation, the system was delivered with a complete set of NeXTSTEP libraries for backward compatibility. This was an easy thing to do in OpenStep due to library versioning, and OPENSTEP did not suffer in bloat because of it.
called OPENSTEP Enterprise (often abbreviated OSE). This was an unintentional demonstration on the true nature of the portability of programs created under the OpenStep specification. Programs for OPENSTEP for Mach could be ported to OSE with little difficulty. This allowed their existing customer base to continue using their tools and applications, but running them on Windows, to which many of them were in the process of switching. Never a clean match from the UI perspective, probably due to OPENSTEP's routing of window graphics through the Display Postscript server—which was also ported to Windows—OSE nevertheless managed to work fairly well and extended OpenStep's commercial lifespan.
OPENSTEP and OSE had two revisions (and one major one that was never released) before NeXT was purchased by Apple in 1997.
appearance from Mac OS 8
and support for Java and Apple's own technologies, including ColorSync
and QuickTime
; it could be regarded as OPENSTEP 5. Two developer versions of Rhapsody were released, known as Developer Preview 1 and 2; these ran on a limited subset of both Intel and PowerPC hardware. Mac OS X Server 1.0
was the first commercial release of this operating system, and was delivered exclusively for PowerPC Mac hardware.
, and responding to developers by including better backward compatibility for Mac OS applications through the addition of Carbon
, Apple released Mac OS X
and Mac OS X Server
, starting at version 10.0.
Mac OS X's primary programming environment is essentially OpenStep (with certain additions such as XML property lists and URL classes for Internet connections) with Mac OS X ports of the development libraries and tools, now called Cocoa
.
Mac OS X has since become the single most popular desktop Unix-like operating system in the world, although Mac OS X is no longer an OpenStep compliant operating system.
implementation of the NeXT
libraries, began at the time of NeXTSTEP, predating OPENSTEP. While OPENSTEP and OSE were purchased by Apple, who effectively ended the commercial development of implementing OpenStep for other platforms, GNUstep is an ongoing open source project aiming to create a portable, free software
implementation of the Cocoa/OPENSTEP libraries.
GNUstep also features a fully functional development environment, reimplementations of some of the newer innovations from Mac OS X's Cocoa
framework, as well as its own extensions to the API.
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
(API) specification for an object-oriented operating system
Object-oriented operating system
An object-oriented operating system is an operating system which internally uses object-oriented methodologies.An object-oriented operating system is in contrast to an object-oriented user interface or programming framework, which can be placed above a non-object-oriented operating system like DOS,...
that used a non-NeXTSTEP
NEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
operating system as its core, principally developed by NeXT
NeXT
Next, Inc. was an American computer company headquartered in Redwood City, California, that developed and manufactured a series of computer workstations intended for the higher education and business markets...
with Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
. OPENSTEP (all capitalized) was a specific implementation of the OpenStep API developed by NeXT. While originally built on a Mach-based Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
(such as the core of NeXTSTEP
NEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
), versions of OpenStep were available for Solaris and Windows NT
Windows NT
Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was intended to complement...
as well. The software libraries that shipped with OPENSTEP are a superset of the original OpenStep specification.
History
The OpenStep API was created as the result of a 1993 collaboration between NeXTNeXT
Next, Inc. was an American computer company headquartered in Redwood City, California, that developed and manufactured a series of computer workstations intended for the higher education and business markets...
and Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
, allowing this cut-down version of NeXT's NeXTSTEP
NEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
object layers to be run on Sun's Solaris operating system (more specifically, Solaris on SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
-based hardware). Most of the OpenStep effort was to strip away those portions of NeXTSTEP that depended on Mach
Mach (kernel)
Mach is an operating system kernel developed at Carnegie Mellon University to support operating system research, primarily distributed and parallel computation. Although Mach is often mentioned as one of the earliest examples of a microkernel, not all versions of Mach are microkernels...
or NeXT-specific hardware being present. This resulted in a smaller system that consisted primarily of Display PostScript
Display PostScript
Display PostScript is an on-screen display system. As the name implies, DPS uses the PostScript imaging model and language to generate on-screen graphics...
, the Objective-C
Objective-C
Objective-C is a reflective, object-oriented programming language that adds Smalltalk-style messaging to the C programming language.Today, it is used primarily on Apple's Mac OS X and iOS: two environments derived from the OpenStep standard, though not compliant with it...
runtime and compilers, and the majority of the NeXTSTEP Objective-C libraries. Not included was the basic operating system, or the display system.
The first draft of the API was published by NeXT in summer 1994. Later that year they released an OpenStep compliant version of their flagship operating system NeXTSTEP
NEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
, rebranded as OPENSTEP and supported on several of their platforms as well as Sun SPARC systems. The official OpenStep API, published in September 1994, was the first to split the API between Foundation and Application Kit and the first to use the "NS" prefix. Early versions of NeXTSTEP used an "NX" prefix and contained only the Application Kit, relying on standard Unix libc types for low-level data structures. OPENSTEP remained NeXT's primary operating system product until they were purchased by Apple Computer
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...
in 1996. OPENSTEP was then combined with technologies from the existing Mac OS
Mac OS
Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...
to produce Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
.
Sun originally adopted the OpenStep environment with the intent of complementing Sun's CORBA
Çorba
Chorba , ciorbă , shurpa , shorpo , or sorpa is one of various kinds of soup or stew found in national cuisines across Middle East...
-compliant object system, Solaris NEO
Distributed Objects Everywhere
Distributed Objects Everywhere was a long-running Sun Microsystems project to build a distributed computing environment based on the CORBA system in the 'back end' and OpenStep as the user interface. First started in 1990 and announced soon thereafter, it remained vaporware for many years before...
(formerly known as Project DOE), by providing an object-oriented user interface toolkit to complement the object-oriented CORBA plumbing. The port involved integrating the OpenStep AppKit with the Display PostScript layer of the Sun X11 server, making the AppKit tolerant of multi-threaded code (as Project DOE was inherently heavily multi-threaded), implementing a Solaris daemon to simulate the behavior of Mach ports, extending the SunPro C++ compiler to support Objective-C
Objective-C
Objective-C is a reflective, object-oriented programming language that adds Smalltalk-style messaging to the C programming language.Today, it is used primarily on Apple's Mac OS X and iOS: two environments derived from the OpenStep standard, though not compliant with it...
using NeXT's ObjC runtime, writing an X11 window manager
Window manager
A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment...
to implement the NeXTSTEP look and feel as much as possible, and integrating the NeXT development tools, such as Project Manager and Interface Builder, with the SunPro compiler. In order to provide a complete end-user environment, Sun also ported the NeXTSTEP-3.3 versions of several end-user applications, including Mail.app, Preview.app, Edit.app, Workspace Manager, and the dock.
The OpenStep and CORBA parts of the products were later split, and NEO was released in late 1995 without the OpenStep environment. In March 1996, Sun announced Joe, a product to integrate NEO with Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
. Sun shipped a beta release of the OpenStep environment for Solaris on July 22, 1996, and made it freely available for download in August 1996 for non-commercial use, and for sale in September 1996. OpenStep/Solaris only shipped for the SPARC architecture.
Description
The API OpenStep contrasts with the earlier NeXTSTEP primarily in five ways:- OpenStep describes only the upper-level libraries and services (like Display PostScriptDisplay PostScriptDisplay PostScript is an on-screen display system. As the name implies, DPS uses the PostScript imaging model and language to generate on-screen graphics...
), whereas NeXTSTEP referred to both these libraries and the operating system as well. - Any code depending entirely on the Mach kernel was removed, so that OpenStep could be run on top of any reasonably powerful operating system.
- A significant amount of effort was put into making the system "endianEndiannessIn computing, the term endian or endianness refers to the ordering of individually addressable sub-components within the representation of a larger data item as stored in external memory . Each sub-component in the representation has a unique degree of significance, like the place value of digits...
-free", an issue NeXT had already faced during a port of NeXTSTEP to the Intel platform. - Low-level objects such as strings were represented with C data types in NeXTSTEP, whereas in OpenStep a number of new classes (NSString, NSNumber, etc.) were introduced to support endian-conversion as well as provide added functionality and become platform-independent. This had ripple-effects throughout the API, mostly for the better. This set of classes (a framework) was called the Foundation KitFoundation KitThe Foundation Kit, or just Foundation for short, is an Objective-C framework in the OpenStep specification. It provides basic classes such as wrapper classes and data structure classes. This framework uses the prefix NS .-NSObject:...
, or just Foundation for short. - OpenStep uses reference countingReference countingIn computer science, reference counting is a technique of storing the number of references, pointers, or handles to a resource such as an object, block of memory, disk space or other resource...
to manage memory and object lifetimes, and provides Autorelease Pools as a form of automatic memory management. NeXTSTEP does not provide reference counted memory management.
The API specification itself is composed of the two main sets of object-oriented classes: the GUI
Gui
Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...
and graphics front-end known as the Application Kit
Application Kit
The Application Kit is a collection of classes within the OpenStep specification and provided by such operating systems as OPENSTEP, GNUstep, and Mac OS X under Cocoa, providing classes oriented around graphical user interface capabilities...
, and the aforementioned Foundation Kit.
However, OpenStep also specified the use of Display PostScript, a versatile and powerful PostScript
PostScript
PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...
-based method of drawing windows and graphics on screen. NeXT, with its devotion to implementing object-oriented solutions, supplied pswraps for interfacing C code to Display PostScript. pswraps acted in an encapsulative way and was somewhat object oriented. The Application Kit, Foundation, and Display PostScript comprise the three key technologies in the OpenStep specification; however, Display PostScript was featured in older NeXT technologies, such as NeXTSTEP.
Building on OpenStep
The standardization on OpenStep also allowed for the creation of several new library packages that were delivered on the OPENSTEP platform. Unlike the operating system as a whole, these packages were designed to run stand-aloneStandalone program
A standalone program is a computer program that does not load any external module, library function, or program and that is designed to boot with the bootstrap procedure of the target processor...
on practically any operating system. The idea was to use OpenStep code as a basis for network-wide applications running across different platforms, as opposed to using CORBA
Çorba
Chorba , ciorbă , shurpa , shorpo , or sorpa is one of various kinds of soup or stew found in national cuisines across Middle East...
or some other system.
Primary among these packages was Portable Distributed Objects
Portable Distributed Objects
Portable Distributed Objects, or PDO, is a programming API for creating object-oriented code that can be executed remotely on a network of computers. It was created by NeXT Computer, Inc. using their OpenStep system, whose use of Objective-C made the package very easy to write...
(PDO). PDO was essentially an even more "stripped down" version of OpenStep containing only the Foundation Kit technologies, combined with new libraries to provide remote invocation with very little code. Unlike OpenStep, which defined an operating system that applications would run in, under PDO the libraries were compiled into the application itself, creating a stand-alone "native" application for a particular platform. PDO was small enough to be easily portable, and versions were released for all major server vendors.
PDO became somewhat infamous in the mid-1990s when NeXT staff took to writing in solutions to various CORBA magazine articles in a few lines of code, whereas the original article would fill several pages. Even though using PDO required the installation of a considerable amount of supporting code (Objective-C and the libraries), PDO applications were nevertheless considerably smaller than similar CORBA solutions, typically about one-half to one-third the size.
The similar D'OLE provided the same types of services, but presented the resulting objects as DCOM
Distributed component object model
Distributed Component Object Model is a proprietary Microsoft technology for communication among software components distributed across networked computers. DCOM, which originally was called "Network OLE", extends Microsoft's COM, and provides the communication substrate under Microsoft's COM+...
objects, with the goal of allowing programmers to create DCOM services running on high-powered platforms, called from Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
applications. For instance one could develop a high-powered financial modeling application using D'OLE, and then call it directly from within Microsoft Excel
Microsoft Excel
Microsoft Excel is a proprietary commercial spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications...
. When D'OLE was first released, OLE by itself only communicated between applications running on a single machine. PDO enabled NeXT to demonstrate Excel talking to other Microsoft applications across a network before Microsoft themselves were able to implement this functionality.
Another package developed on OpenStep was Enterprise Objects Framework
Enterprise Objects Framework
The Enterprise Objects Framework was introduced by NeXT in 1994 as a pioneering object-relational mapping product for its NeXTSTEP and OpenStep development platforms. The EOF abstracts the process of interacting with a relational database, mapping database rows to Java or Objective-C objects. This...
(EOF), a tremendously powerful (for the time) object-relational mapping
Object-relational mapping
Object-relational mapping in computer software is a programming technique for converting data between incompatible type systems in object-oriented programming languages. This creates, in effect, a "virtual object database" that can be used from within the programming language...
product. EOF became very popular in the enterprise market, notably in the financial sector where OPENSTEP caused something of a minor revolution.
OPENSTEP for Mach
NeXT's first operating system was NeXTSTEPNEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
, a sophisticated Mach-UNIX based operating system that originally ran only on NeXT's Motorola 68k-based workstations and that was then ported to run on 32-bit Intel x86
IA-32
IA-32 , also known as x86-32, i386 or x86, is the CISC instruction-set architecture of Intel's most commercially successful microprocessors, and was first implemented in the Intel 80386 as a 32-bit extension of x86 architecture...
-based "IBM-compatible" personal computers
IBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
, PA-RISC
PA-RISC
PA-RISC is an instruction set architecture developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer architecture, where the PA stands for Precision Architecture...
-based workstations from Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
, and SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
-based workstations from Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
.
NeXT completed an implementation of OpenStep on their existing Mach-based OS and called it OPENSTEP for Mach 4.0, 4.1 and 4.2. It was, for all intents, NeXTSTEP 4.0, and still retained flagship NeXTSTEP technologies (such as DPS
Display PostScript
Display PostScript is an on-screen display system. As the name implies, DPS uses the PostScript imaging model and language to generate on-screen graphics...
, UNIX underpinnings, user interface characteristics like the Dock
Dock (computing)
The Dock is a prominent feature of the graphical user interface of the Mac OS X operating system. It is used to launch applications and switch between running applications...
and Shelf
Shelf (computing)
The Shelf is an interface feature in NeXTSTEP and OPENSTEP, and is used as a repository to store links to commonly used files, directories and programs, and as a temporary "holding" place to move/copy files and directories around in the file system hierarchy...
, and so on), and retained the classic NeXTSTEP user interface and styles. OPENSTEP for Mach was further improved, in comparison to NeXTSTEP 3.3, with vastly improved driver support – however the environment to actually write drivers was changed with the introduction of the object-oriented DriverKit.
OPENSTEP for Mach supported Intel x86-based PC's, Sun's SPARC workstations, and NeXT's own 68k-based architectures, while the HP PA-RISC version was dropped. These versions continued to run on the underlying Mach-based OS used in NeXTSTEP. OPENSTEP for Mach became NeXT's primary OS from 1995 on, and was used mainly on the Intel platform. In addition to being a complete OpenStep implementation, the system was delivered with a complete set of NeXTSTEP libraries for backward compatibility. This was an easy thing to do in OpenStep due to library versioning, and OPENSTEP did not suffer in bloat because of it.
Solaris OpenStep
In addition to the OPENSTEP for Mach port for SPARC, Sun and NeXT developed an OpenStep compliant set of frameworks to run on Sun's Solaris operating system. After developing Solaris OpenStep, Sun lost interest in OpenStep and shifted its attention toward Java. As a virtual machine development environment, Java served as a direct competitor to OpenStep.OPENSTEP Enterprise
NeXT also delivered an implementation running on top of Windows NT 4.0Windows NT 4.0
Windows NT 4.0 is a preemptive, graphical and business-oriented operating system designed to work with either uniprocessor or symmetric multi-processor computers. It was the next release of Microsoft's Windows NT line of operating systems and was released to manufacturing on 31 July 1996...
called OPENSTEP Enterprise (often abbreviated OSE). This was an unintentional demonstration on the true nature of the portability of programs created under the OpenStep specification. Programs for OPENSTEP for Mach could be ported to OSE with little difficulty. This allowed their existing customer base to continue using their tools and applications, but running them on Windows, to which many of them were in the process of switching. Never a clean match from the UI perspective, probably due to OPENSTEP's routing of window graphics through the Display Postscript server—which was also ported to Windows—OSE nevertheless managed to work fairly well and extended OpenStep's commercial lifespan.
OPENSTEP and OSE had two revisions (and one major one that was never released) before NeXT was purchased by Apple in 1997.
Rhapsody, Mac OS X Server 1.0
After acquiring NeXT, Apple intended to ship Rhapsody as a reworked version of OPENSTEP for Mach for both the Mac and standard PCs. Rhapsody was OPENSTEP for Mach with a CoplandCopland (operating system)
Copland was a project at Apple Computer to create an updated version of the Macintosh operating system. It was to have introduced protected memory, preemptive multitasking and a number of new underlying operating system features, yet still be compatible with existing Mac software...
appearance from Mac OS 8
Mac OS 8
Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It represented the largest overhaul of the Mac OS since the release of System 7, some six years previously. It puts more emphasis on color than previous operating systems...
and support for Java and Apple's own technologies, including ColorSync
ColorSync
ColorSync is Apple Inc's color management API for the Mac OS and Mac OS X.-Version history:Apple developed the original 1.0 version of ColorSync as a Mac-only architecture, which made it into an operating system release in 1993. In the same year, Apple co-founded the International Color Consortium...
and QuickTime
QuickTime
QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...
; it could be regarded as OPENSTEP 5. Two developer versions of Rhapsody were released, known as Developer Preview 1 and 2; these ran on a limited subset of both Intel and PowerPC hardware. Mac OS X Server 1.0
Mac OS X Server 1.0
Mac OS X Server 1.0, released on March 16, 1999, is the first operating system released into the retail market by Apple Computer based on their acquisition of NeXT. It followed the Rhapsody series of developer releases of what was to be known as Mac OS X...
was the first commercial release of this operating system, and was delivered exclusively for PowerPC Mac hardware.
Mac OS X 10.0 and later
After replacing the Display Postscript WindowServer with QuartzQuartz (graphics layer)
Quartz specifically refers to a pair of Mac OS X technologies, each part of the Core Graphics framework: Quartz 2D and Quartz Compositor. It includes both a 2D renderer in Core Graphics and the composition engine that sends instructions to the graphics card...
, and responding to developers by including better backward compatibility for Mac OS applications through the addition of Carbon
Carbon (API)
Carbon is one of Apple Inc.'s procedural application programming interfaces for the Macintosh operating system. It provides C programming language access to Macintosh system services...
, Apple released Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
and Mac OS X Server
Mac OS X Server
Mac OS X Server is a Unix server operating system from Apple Inc. The server edition of Mac OS X is architecturally identical to its desktop counterpart, except that it includes work group management and administration software tools...
, starting at version 10.0.
Mac OS X's primary programming environment is essentially OpenStep (with certain additions such as XML property lists and URL classes for Internet connections) with Mac OS X ports of the development libraries and tools, now called Cocoa
Cocoa (API)
Cocoa is Apple's native object-oriented application programming interface for the Mac OS X operating system and—along with the Cocoa Touch extension for gesture recognition and animation—for applications for the iOS operating system, used on Apple devices such as the iPhone, the iPod Touch, and...
.
Mac OS X has since become the single most popular desktop Unix-like operating system in the world, although Mac OS X is no longer an OpenStep compliant operating system.
GNUstep
GNUstep, a free softwareFree software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
implementation of the NeXT
NeXT
Next, Inc. was an American computer company headquartered in Redwood City, California, that developed and manufactured a series of computer workstations intended for the higher education and business markets...
libraries, began at the time of NeXTSTEP, predating OPENSTEP. While OPENSTEP and OSE were purchased by Apple, who effectively ended the commercial development of implementing OpenStep for other platforms, GNUstep is an ongoing open source project aiming to create a portable, free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
implementation of the Cocoa/OPENSTEP libraries.
GNUstep also features a fully functional development environment, reimplementations of some of the newer innovations from Mac OS X's Cocoa
Cocoa (API)
Cocoa is Apple's native object-oriented application programming interface for the Mac OS X operating system and—along with the Cocoa Touch extension for gesture recognition and animation—for applications for the iOS operating system, used on Apple devices such as the iPhone, the iPod Touch, and...
framework, as well as its own extensions to the API.