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OpenStep is an object-oriented application programming interface (API) specification for a legacy object-oriented operating system, with the basic goal of offering a NeXTSTEP-like environment on a non-NeXTSTEP operating system. OpenStep was principally developed by NeXT with Sun Microsystems, to allow NeXTSTEP (like) development on Sun's operating systems, specifically Solaris. NeXT produced a version of OpenStep for their own Mach-based Unix, known as OPENSTEP (all capitalized),〔(Toastytech.com )〕 as well as a version that ran on Windows NT. The software libraries that shipped with OPENSTEP are a superset of the original OpenStep specification, including many features from the original NeXTSTEP. ==History== The OpenStep API was created as the result of a 1993 collaboration between NeXT and Sun Microsystems, allowing this cut-down version of the 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 lower-level 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 NeXTSTEP as OPENSTEP, 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.〔(Cocoa Fundamentals Guide: A Bit of History )〕 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. iPhone and iPad's iOS is also a descendant of OPENSTEP, but targeted at touch devices. 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 was shipped only for the SPARC architecture. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「OpenStep」の詳細全文を読む スポンサード リンク
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