* Attached Support Processor, one of the two early IBM System / 360 programs that replaces the native SPOOL facilities of OS / 360 ; the other was Houston Automatic Spooling Priority ( HASP ).

With ASP Version 3 the name was changed to Asymmetric Multiprocessor and support was added for OS / VS2 ( SVS ).

* Auxiliary Storage Pool, a group of disk drives in the IBM i ( aka OS / 400 ) operating system

Three emulators of the machine exist, ElectrEm for Windows / Linux / Mac OS X, Elkulator for Windows / DOS and the Multi-system emulator MESS.

The rise of TCP / IP during the 1990s led to a re-implementation of most of these types of support on that protocol, and AppleTalk became unsupported as of the release of Mac OS X v10. 6 in 2009.

| ATA / ATAPI-8 || ATA-8 || — || || Hybrid drive featuring non-volatile cache to speed up critical OS files || In progress

( Around 1990, OS / 2 came out with " preemptive multitasking " of DOS, an alternative to DESQview for multi-node BBS.

By 1995, many of the DOS-based BBSes had begun switching to modern multitasking operating systems, such as OS / 2, Windows 95, and Linux.

JPI first launched a MS-DOS compiler named JPI Modula-2, that later became TopSpeed Modula-2, and followed up with TopSpeed C, TopSpeed C ++ and TopSpeed Pascal compilers for both the MS-DOS and OS / 2 operating systems.

MS-DOS and Win16 subsystems ( only on i386 ) can run some applications for those platforms, and it has an OS / 2 subsystem for running CLI OS / 2 applications.

IBM contributed its Common User Access model from OS / 2's Workplace Shell.

OS / 390 or its successor, z / OS, display dates in yy. ddd format for most operations.

* On systems that support one-button mice, context menus are typically opened by pressing and holding the primary mouse button ( this works on the icons in the Dock on Mac OS X ) or by pressing a keyboard / mouse button combination ( e. g. Ctrl-mouse click in Mac OS ).

Debian GNU / Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential Linux distribution.

* Open Dylan-Host of two open source, optimizing Dylan compilers targeting Unix / Linux, Mac OS X, and Microsoft Windows

EFI booting has been supported in only Microsoft Windows versions supporting GPT, the Linux kernel 2. 6. 1 and later, and Mac OS X on Intel-based Macs.

; Macintosh Common Lisp: Version 5. 2 for Apple Macintosh computers with a PowerPC processor running Mac OS X is open source.

* Installable File System ( IFS ) – a filesystem API for IBM OS / 2 and Microsoft Windows NT

Originally developed on IRIX, Freeciv has been ported to many different operating systems: it is distributed with many Linux distributions, offers installers for Microsoft Windows, and has been known to run on Mac OS X, Solaris, Ultrix, QNX, OS / 2, Cygwin, AmigaOS, RISC OS, Maemo, ZETA, SkyOS and various BSDs.

This allowed the game to be ported to different platforms such as Linux and OS / 2 ( EComStation ).

Modern Windows operating system versions are based on the newer Windows NT kernel that was originally intended for OS / 2.

Version 2. 03, and later 3. 0, faced challenges from Apple over its overlapping windows and other features Apple charged mimicked the ostensibly copyrighted " look and feel " of its operating system and " embodie and generated a copy of the Macintosh " in its OS.

OS / 2 logo

During the mid to late 1980s, Microsoft and IBM had cooperatively been developing OS / 2 as a successor to DOS.

OS / 2 would take full advantage of the aforementioned protected mode of the Intel 80286 processor and up to 16 MB of memory.

OS / 2 1. 0, released in 1987, supported swapping and multitasking and allowed running of DOS executables.

A GUI, called the Presentation Manager ( PM ), was not available with OS / 2 until version 1. 1, released in 1988.

Microsoft wanted to further develop Windows, while IBM desired for future work to be based on OS / 2.

In an attempt to resolve this tension, IBM and Microsoft agreed that IBM would develop OS / 2 2. 0, to replace OS / 2 1. 3 and Windows 3. 0, while Microsoft would develop a new operating system, OS / 2 3. 0, to later succeed OS / 2 2. 0.

On the other hand, Mac OS X has since version 10. 6 shown hard drive size using decimal prefixes ( thus matching the drive makers ' packaging ).

SOE released a Mac OS X version of EverQuest in 2003, incorporating all expansions through Planes of Power.

SOE has devoted one server ( Al ' Kabor ) to an OS X version of the game.

After an interim 1. 3 version to fix up many remaining problems with the 1. x series, IBM released OS / 2 version 2. 0 in 1992.

Responding to complaints about OS / 2 2. 0's high demands on computer hardware, version 3. 0 was significantly optimized both for speed and size.

Several versions are available for the UNIX-based Mac OS X, including a text-mode version using Fink or MacPorts and two graphical versions, IrssiX, and MacIrssi.

The choice that OS system developers faced was either to start from scratch and create an OS that would not run the vast majority of the old programs or to come up with a version of DOS that was slow and ugly but still would run a majority of the old programs.

The same limitations affected Digital Research's FlexOS 286 version 1. 0, a derivation of Concurrent DOS 286, developed in 1986, introduced in January 1987, and later adopted by IBM for their IBM 4690 OS.

Privacy extensions are enabled by default in Windows, Mac OS X ( since 10. 7 ), and iOS ( since version 4. 3 ).

The release of an open source version as well as ports to GNU / Linux and Mac OS X was announced in May 2010, but the release date of December 2011 was postponed to 30th October 2012 ( Alpha release ).

The software was re-designed and re-written for portability ( versions for GNU / Linux and Mac OS X have been promised ) and now supports many more codecs including AVCHD, H. 264, AVC-Intra, DNxHD, ProRes, Red R3D, DPX, XDCAM HD 50, XDCAM EX, DVD, Blu-ray, and 4K, but only for the paid Pro version.

As of June 2012, EditShare has not released an open source version and the GNU / Linux and Mac OS platform releases have been delayed.

The first phone to use the newest version of Google's open source OS, Android 2. 0, was released on November 2, 2009 as the Motorola Droid ( the GSM version launched a month later, in Europe, as the Motorola Milestone ).

It was the final version of Mac OS X to support the PowerPC architecture.

For most users, the most noticeable changes are: the disk space that the operating system frees up after a clean install compared to Mac OS X 10. 5 Leopard, a more responsive Finder rewritten in Cocoa, faster Time Machine backups, more reliable and user friendly disk ejects, a more powerful version of the Preview application, as well as a faster Safari web browser.

Those who opposed Microsoft's position countered that the browser was still a distinct and separate product which did not need to be tied to the operating system, since a separate version of Internet Explorer was available for Mac OS.

Mach 3 led to a number of efforts to port other operating systems parts for the microkernel, including IBM's Workplace OS and several efforts by Apple Computer to build a cross-platform version of the Mac OS.

A server version of the new operating system was released as Mac OS X Server 1. 0 in 1999, and the first consumer version, Mac OS X 10. 0, in 2001.