Editing Object-oriented operating system

{{Short description|Operating system}}
An '''object-oriented operating system'''<ref name=":0"/> is an [[operating system]] that is designed, structured, and operated using [[object-oriented programming]] principles.

An object-oriented operating system is in contrast to an object-oriented [[user interface]] or programming [[Software framework|framework]], which can be run on a non-object-oriented operating system like [[DOS]] or [[Unix]].

There are already [[object-based language]] concepts involved in the design of a more typical operating system such as [[Unix]]. While a more traditional language like [[C (programming language)|C]] does not support object-orientation as fluidly as more recent languages, the notion of, for example, a [[Computer file|file]], [[Stream (computing)|stream]], or [[device driver]] (in Unix, each represented as a [[file descriptor]]) can be considered a good example of objects. They are, after all, [[abstract data type]]s, with various [[Method (computer programming)|methods]] in the form of [[system call]]s which behavior varies based on the type of object and which implementation details are hidden from the caller.

[[Object-oriented programming|Object-orientation]] has been defined as [[Object (computer science)|objects]] + [[Inheritance (object-oriented programming)|inheritance]], and inheritance is only one approach to the more general problem of [[Delegation (computing)|delegation]] that occurs in every operating system.<ref>{{cite journal |last=Wegner |first=Peter |date=December 1987 |title=Dimensions of Object-based Language Design |journal=ACM SIGPLAN Notices |volume=22 |issue=12 |pages=168–182 |doi=10.1145/38807.38823}} Also in Conference Proceedings on Object-oriented Programming Systems, Languages.</ref> Object-orientation has been more widely used in the [[user interface]]s of operating systems than in their [[Kernel (operating system)|kernels]].

== Background ==
An object is an instance of a class, which provides a certain set of functionalities. Two objects can be differentiated based on the functionalities (or methods) they support. In an operating system context, objects are associated with a resource. Historically, the object-oriented design principles were used in operating systems to provide several protection mechanisms.<ref name=":0">{{cite book |last1=Pashtan |first1=Ariel |title=Proceedings of the ACM '82 conference on - ACM 82 |chapter=Object oriented operating systems |date=1 January 1982 |pages=126–131 |doi=10.1145/800174.809777 |chapter-url=https://dl.acm.org/doi/10.1145/800174.809777 |publisher=Association for Computing Machinery (ACM)|isbn=9780897910859 |s2cid=9463966 }}</ref>

Protection mechanisms in an operating system help in providing a clear separation between different user programs. It also protects the operating system from any malicious user program behavior. For example, consider the case of user profiles in an operating system. The user should not have access to resources of another user. The object model deals with these protection issues with each resource acting as an object. Every object can perform only a set of operations. In the context of user profiles, the set of operations is limited by [[privilege level]] of a user.<ref name=":0"/>

Present-day operating systems use object-oriented design principles for many components of the system, which includes protection.

== Examples ==
; Athene
:Athene is an object-based operating system first released in 2000 by Rocklyte Systems.<ref>{{cite web |title=The Athene Operating System |url=https://lwn.net/Articles/102230/ |website=LWN.net |access-date=13 February 2017}}</ref><ref>{{cite web |title=Rocklyte Systems |url=http://www.rocklyte.com/ |website=Rocklyte Systems |access-date=2007-02-18 |archive-date=2006-11-03 |archive-url=https://web.archive.org/web/20061103022452/http://rocklyte.com/ |url-status=dead }}</ref> The user environment was constructed entirely from objects that are linked together at runtime. Applications for Athene could also be created using this methodology and were commonly scripted using the object scripting language Dynamic Markup Language (DML). Objects could have been shared between processes by creating them in [[shared memory]] and locking them as needed for access. Athene's object framework was multi-platform, allowing it to be used in Windows and Linux environments for developing object-oriented programs. The company went defunct and the project abandoned sometime in 2009.
; BeOS
:[[BeOS]]<ref>{{cite book|last1=Sydow|first1=Dan Parks|title=Programming the Be operating system|date=1999|publisher=O'Reilly|location=Beijing|isbn=978-1-56592-467-3|edition=1st}}</ref> was an object-oriented operating system released in 1995, which used objects and the [[C++]] language for the [[API|application programming interface]] (API). The kernel was written in C with C++ wrappers in user space. The OS did not see mainstream usage and proved commercially unviable, however it has seen continued usage and development by a small enthusiast community.
; {{Anchor|Choices}}Choices
:Choices is an object-oriented operating system developed at the [[University of Illinois at Urbana–Champaign]].<ref>{{cite journal |last1=Campbell |first1=Roy |last2=Johnston |first2=Garry |last3=Russo |first3=Vincent |date=1 July 1987 |title=Choices (Class Hierarchical Open Interface for Custom Embedded Systems) |journal=ACM SIGOPS Operating Systems Review |volume=21 |issue=3 |pages=9–17 |doi=10.1145/29321.29323 |s2cid=11935474 |issn=0163-5980|doi-access=free }}</ref><ref>{{cite web |title=Choices |url=http://choices.cs.illinois.edu/ |website=choices.cs.illinois.edu}}</ref> It is written in [[C++]] and uses objects to represent core kernel components like the [[central processing unit]] (CPU), [[Process (computing)|processes]], and so on. [[Inheritance (object-oriented programming)|Inheritance]] is used to separate the kernel into portable machine-independent classes and small non-portable dependent classes. Choices has been ported to and runs on [[SPARC]], [[x86]], and [[ARM architecture family|ARM]].
; ETHOS
:ETHOS was an experimental object oriented version of the Oberon System (see below) created by Clemens Szyperski for his PhD Thesis<ref>{{Cite thesis |type=PhD |last=Szyperski |first=Clemens |date=1992 |title=Insight ETHOS: On Object-Orientation in Operating Systems |publisher=[[ETH Zürich]] |place=Zurich, Switzerland |isbn=3-7281-1948-2}} [http://e-collection.library.ethz.ch/eserv/eth:38713/eth-38713-02.pdf ETHZ ecollection].</ref> written in [[Oberon-2]]
; GEOS
:[[GEOS (16-bit operating system)|PC/GEOS]] is a light-weight object-oriented multitasking graphical operating system with sophisticated window and desktop management featuring scalable fonts. It is mostly written in an object-oriented x86 assembly language dialect and some C/C++ and is designed to run on [[DOS]] (similar to Microsoft Windows up to [[Windows Me]]). GEOS was developed originally by [[Berkeley Softworks]] in 1990, which later became GeoWorks Corporation, and it is continued to be maintained by BreadBox Computer Company. Related [[software suite]]s were named ''Ensemble'' and ''New Deal Office''. Adaptations exist for various palmtops, and 32-bit systems with non-x86-CPUs.
; Haiku
:[[Haiku (operating system)|Haiku]] (originally named ''OpenBeOS''), is an open-source replacement for BeOS. It reached its first development milestone in September 2009 with the release of Haiku R1/Alpha 1. The x86 distribution is compatible with BeOS at both source and binary level. Like BeOS, it is written primarily in [[C++]] and provides an object-oriented API. It is actively developed.
; IBM i (OS/400, i5/OS) 
:IBM introduced [[OS/400]] in 1988. This OS ran exclusively on the [[AS/400]] platform. Renamed [[IBM i]] in 2008, this operating system and runs exclusively on [[IBM Power Systems|Power Systems]] which also can run [[IBM AIX|AIX]] and [[Linux]]. IBM i uses an object-oriented methodology and integrates a database ([[Db2 for i]]). The IBM i OS has a 128-bit unique identifier for each object.
; IBM OS/2 2.0
:IBM's first priority based pre-emptive multitasking, graphical, windows-based operating system included an object-oriented user shell. It was designed for the Intel 80386 that used [[virtual 8086 mode]] with full 32-bit support and was released in 1992. [[ArcaOS]], a new OS/2 based operating system initially called Blue Lion<ref>{{Cite news|url=https://www.arcanoae.com/blue-lion/|title=Blue Lion, by Arca Noae|newspaper=Arca Noae|access-date=2017-02-18|language=en-US}}</ref> is being developed by Arca Noae. The first version was released in May 2017.
; IBM TopView
:[[IBM TopView|TopView]] was an object-oriented operating environment that loaded on a PC on DOS, and then took control from DOS. At that point it effectively became an object-oriented operating system with an object-oriented API (TopView API). It was IBM's first multi-tasking, window based, object-oriented operating system for the PC led by David C. Morrill and released in February 1985.
; Java-based
:Given that [[Oracle Corporation|Oracle's]] (formerly [[Sun Microsystems]]') [[Java (programming language)|Java]] is today one of the most dominant object-oriented languages, it is no surprise that Java-based operating systems have been attempted. In this area, ideally, the [[kernel (operating system)|kernel]] would consist of the bare minimum needed to support a [[Java virtual machine]] (JVM). This is the only component of such an operating system that would have to be written in a language other than Java. Built on the JVM and basic hardware support, it would be possible to write the rest of the operating system in Java; even parts of the system that are more traditionally written in a lower-level language such as C, for example [[device driver]]s, can be written in Java.
:Examples of attempts at such an operating system include [[JavaOS]], JOS,<ref>{{cite web
 | url = http://jos.sourceforge.net/about.html
 | title = About
 | publisher = JOS (A Free Java-Based Operating System)
 | quote = The JOS Project is a collaborative undertaking by an international group of Java™ programmers and enthusiasts aimed at the creation of a free and open Java™ based Operating System (JOS). As a collaborative effort, we work together to research how a Java-based operating system should work. Together, we work to build components for a Java-based operating system.
 | access-date = 2012-09-03
}}</ref> JNode, and [[JX (operating system)|JX]].
; Lisp-based
:An object-oriented operating system written in the [[Lisp (programming language)|Lisp]] dialect [[Lisp Machine Lisp]] (and later [[Common Lisp]]) was developed at MIT. It was commercialized with [[Lisp machine]]s from [[Symbolics]], [[Lisp Machines|Lisp Machines Inc.]] and [[Texas Instruments]]. Symbolics called their operating system [[Genera (operating system)|Genera]]. It was developed with the [[Flavors (programming language)|Flavors]] object-oriented extension of Lisp, then with New Flavors, and then with the [[Common Lisp Object System]] (CLOS).
:Xerox developed several workstations with an operating system written in [[Interlisp-D]]. Interlisp-D provided object-oriented extensions like LOOPS and CLOS.
:Movitz and [https://github.com/froggey/Mezzano Mezzano] are two more recent attempts at operating systems written in Common Lisp.
; Medos-2
:[[Lilith (computer)#Operating system|Medos-2]] is a single user, object-oriented operating system made for the [[Lilith (computer)|Lilith]] line of [[workstation]]s (processor: [[Advanced Micro Devices]] (AMD) [[AMD Am2900|2901]]), developed in the early 1980s at [[ETH Zurich]] by Svend Erik Knudsen with advice from [[Niklaus Wirth]]. It is built entirely from modules of the programming language [[Modula-2]].<ref>
{{Cite thesis |last=Knudsen |first=Svend Erik |date=1983 |title=Medos-2: A Modula-2 Oriented Operating System for the Personal Computer Lilith |type=PhD |publisher=[[ETH Zurich]] |doi=10.3929/ethz-a-000300091|hdl=20.500.11850/137906 }}<!-- also at http://e-collection.library.ethz.ch/eserv/eth:21975/eth-21975-02.pdf --></ref><ref>
{{Cite book |last=Knudsen |first=Svend Erik |date=25 October 2000 |chapter=Medos in Retrospect |editor1-last=Böszörményi |editor1-first=László |editor2-last=Gutknecht |editor2-first=Jürg |editor2-link=Jürg Gutknecht |editor3-last=Pomberger |editor3-first=Gustav |title=The School of Niklaus Wirth: The Art of Simplicity |pages=69–86 |publisher=Morgan Kaufmann |isbn=978-1558607231}} {{ISBN|1-55860-723-4}} & dpunkt, {{ISBN|3-932588-85-1}}.</ref><ref>
{{Cite magazine |last=Sand |first=Paul A. |date=September 1984 |title=The Lilith Personal Computer |magazine=[[Byte (magazine)|Byte]] |pages=300–311 |url=https://archive.org/details/BYTE_Vol_09-10_1984-09_Computer_Graphics/page/n309/mode/2up |access-date=6 March 2021}} Reprint.</ref> It was succeeded at ETH Zurich by the [[Oberon (operating system)|Oberon]] system (see also below), and a variant named ''[[Kronos (computer)#Operating system|Excelsior]]'' was developed for the [[Kronos (computer)|Kronos]] workstation, by the [[Academy of Sciences of the Soviet Union]], Siberian branch, [[Novosibirsk]] Computing Center, Modular Asynchronous Developable Systems (MARS) project, Kronos Research Group (KRG).<ref name="Kronos-Excelsior">{{Cite web |last1=Kuznetsov |first1=D.N. |last2=Nedorya |first2=A.E. |last3=Tarasov |first3=E.V. |last4=Filippov |first4=V.E. |date=<!-- Undated --> |title=Kronos: a family of processors for high-level languages |url=http://www.kronos.ru/literature/processors |website=Kronos: History of a Project |publisher=xTech |language=ru |access-date=13 April 2021}}</ref>
; Microsoft Singularity
:[[Singularity (operating system)|Singularity]] is an experimental operating system based on Microsoft's [[.NET Framework]]. It is comparable to Java-based operating systems.
; Microsoft Windows NT
:[[Windows NT]] is a family of operating systems (including [[Windows 7]], [[Windows 8.1|8]], [[Windows Phone 8.1|Phone 8]], [[8.1]], [[Windows 10]], [[Windows 10 Mobile|10 Mobile]], [[Windows 11]] and [[Xbox#Consoles|Xbox]]) produced by [[Microsoft]], the first version of which was released in July 1993. It is a [[high-level programming language]]-based, [[Cross-platform#Hardware platforms|processor-independent]], [[multiprocessing]], [[multi-user]] operating system. It is best described as [[Object-based language|object-based]] rather than object-oriented as it does not include the full inheritance properties of object-oriented languages.<ref>{{Cite web|title=Object-Based|url=https://msdn.microsoft.com/en-us/library/windows/hardware/ff557751(v=vs.85).aspx|publisher=Microsoft Hardware Development Centre|access-date=Aug 23, 2015}}</ref>
:The [[Object Manager (Windows)|Object Manager]] is in charge of managing NT objects. As part of this responsibility, it maintains an internal [[namespace]] where various operating system components, device drivers, and [[Windows API#Versions|Win32 programs]] can store and lookup objects. The NT [[Native API]] provides routines that allow [[user space]] (mode) programs to browse the namespace and query the status of objects located there, but the interfaces are undocumented.<ref>{{cite book 
 | last = Nebbett
 | first = Gary 
 | date = February 20, 2000
 | title = Windows NT/2000 Native API Reference
 | publisher = Sams Publishing
 | page = 528
 | isbn = 978-1578701995
 | quote = The Windows NT/2000 Native API Reference provides the first comprehensive look at these undocumented services. A unique tool for software developers, this reference includes documentation of over 200 routines included in the native API, detailed description of routines that are either not directly accessible via the Win32 API, or that offer substantial additional functionality.
}}</ref> NT supports per-object (file, function, and role) [[access control list]]s allowing a rich set of security permissions to be applied to systems and services. WinObj is a Windows NT program that uses the NT Native API (provided by NTDLL.DLL) to access and display information on the NT Object Manager's name space.<ref>{{cite web
 | url = https://technet.microsoft.com/en-us/sysinternals/bb896657.aspx
 | title = Windows Sysinternals WinObj
 | last = Russinovich
 | first = Mark
 | publisher = Microsoft
 | quote = Obj is a must-have tool if you are a system administrator concerned about security, a developer tracking down object-related problems, or just curious about the Object Manager namespace.
 | access-date = 2014-05-16
}}</ref>
:; Component Object Model
::On the [[User space|user mode]] side of Windows, the [[Component Object Model]] (COM) is an [[application binary interface]] standard for [[Component-based software engineering|software components]] introduced by [[Microsoft]] in 1993. It is used to enable [[interprocess communication]] and dynamic [[Object (computer science)|object]] creation in a large range of [[programming language]]s. COM is the basis for several other Microsoft technologies and frameworks, including [[Object Linking and Embedding]] (OLE), [[OLE Automation]], [[ActiveX]], [[COM+]], [[Distributed Component Object Model]] (DCOM), the [[Windows shell]], [[DirectX]], and [[Windows Runtime]]. OLE is a [[proprietary format|proprietary]] technology developed by [[Microsoft]] that allows embedding and [[hyperlink|linking]] to [[document]]s and other objects. On a technical level, an OLE object is any object that implements the ''IOleObject'' interface, possibly along with a wide range of other interfaces, depending on the object's needs. Its primary use is for managing [[compound document]]s, but it is also used for transferring data between different [[application software|applications]] using [[drag and drop]] and [[Clipboard (computing)|clipboard]] operations.
:; Compound File Binary Format
::[[Compound File Binary Format]] (CFBF) is a file format for storing many files and streams within one file on a disk. CFBF is developed by Microsoft and is an implementation of Microsoft [[COM Structured Storage]]. Structured storage is widely used as main file format in Microsoft Office applications including [[Microsoft Word]], [[Microsoft Excel]], Microsoft [[Microsofot PowerPoint|PowerPoint]], [[Microsoft Access]] and is the basis of [[Advanced Authoring Format]].
:; Object Linking and Embedding
::Object Linking and Embedding (OLE) was part of a grander plan named [[Cairo (operating system)|Cairo]], the code name for a project at Microsoft from 1991 to 1996. Its charter was to build technologies for a next generation operating system that would fulfill [[Bill Gates]]' vision of "''information at your fingertips''".<ref>{{cite web
 | url = https://www.youtube.com/watch?v=kL8zoQVJaD8
 | title = "Information at Your Fingertips" Keynote - Comdex/Fall 1990 
 |last=Gates |first=Bill |author-link=Bill Gates
 | date = 1990
 | publisher = Microsoft
 | quote = Bill Gates delivered on November 12, 1990 his famous Keynote titled "Information at Your Fingertips"
 | access-date = 2014-05-16
}}</ref><ref>{{cite web
 | url = https://www.youtube.com/watch?v=o0O0Xjpjvfc
 | title = "Information at Your Fingertips" #2 Keynote (The Road Ahead) – Comdex 1994 
 |last=Gates |first=Bill |author-link=Bill Gates
 | date = 1994
 | publisher = Microsoft
 | quote = Bill Gates' "Information At Your Fingertips" keynote speech for Comdex 1995 became the basis for his book The Road Ahead, predicting the next decade in technology – right and wrong. These predictions are enlivened by the interaction between Gates speaking and a made-for-Comdex future crime show.
 | access-date = 2014-05-16
}}</ref> Cairo [[Vaporware|never shipped]], although parts of its technologies have since appeared in other products. The [[Windows 95]] [[graphical user interface]] was based on the initial design work that was done on the Cairo user interface. The remaining component is the [[object-based file system]]. It was once planned to be implemented in the form of Windows Future Storage ([[WinFS]]) as part of [[Windows Vista]]. WinFS is the code name for data storage and [[data management|management]] system project based on [[relational database]]s, running on the Windows NT [[file system]] ([[NTFS]]), which is object-oriented in that it can store the NT objects including its NT object identifier. Each NTFS object has an object identifier; a shortcut with a target that's on an NTFS volume also records the object identifier of the shortcut target, and the object identifier of the drive.<ref>{{cite web
 | url = https://technet.microsoft.com/de-at/magazine/2009.10.windowsconfidential.aspx
 | title = Windows Confidential: The NT Way (excerpts from "The Old New Thing" book)
 |last=Chen |first=Raymond
 | date = 2007
 | publisher = Microsoft
 | quote = The Windows NT file system folks looked at the Windows 95 shortcut resolution algorithm and scoffed. " We can do better than that: We're object-oriented!" Each NTFS object has an object identifier; a shortcut with a target that's on an NTFS volume also records the object identifier of the shortcut target, as well as the object identifier of the drive itself. 
 | access-date = 2014-05-16
}}</ref> WinFS was first demonstrated in 2003 as an advanced storage subsystem for the [[Microsoft Windows]] [[operating system]], designed for [[Persistence (computer science)|persistence]] and management of [[Structured data|structured]], [[Semi-structured model|semi-structured]], and [[unstructured data]]. WinFS development was cancelled in June 2006, with some of its technologies merged into other Microsoft products such as [[Microsoft SQL Server]] 2008 and [[SharePoint|Microsoft SharePoint]]. It was subsequently confirmed in an interview with Bill Gates that Microsoft planned to migrate applications like [[Windows Media Player]], [[Windows Photo Gallery]], [[Microsoft Office Outlook]], etc., to use [[WinFS]] as the data storage back-end.<ref>{{cite web|last=Kornev|first=Daniel |url=http://channel9.msdn.com/ShowPost.aspx?PostID=267149|title=A few words about WinFS: The project is back on track|publisher=Channel 9|date=December 19, 2006}}</ref>
; NeXTSTEP
:During the late 1980s, [[Steve Jobs]] formed the computer company [[NeXT]]. One of NeXT's first tasks was to design an object-oriented operating system, [[NeXTSTEP]]. They did this by adding an object-oriented framework on [[Mach (kernel)|Mach]] and [[Berkeley Software Distribution|BSD]] using the [[Objective-C]] language as a basis. It achieved a niche status in the computing market, notably used by [[Tim Berners-Lee]] developing the first implementation of the [[World Wide Web]].
:NeXTStep later evolved into [[OpenStep]] and the [[Cocoa (API)|Cocoa API]] on [[macOS]] and [[iOS]] ([[iPadOS]], [[watchOS]]).
:OpenStep was provided as an API layer on many operating systems, namely [[HP-UX]], NextStep, [[Solaris (operating system)|Solaris]], and Windows.
; Oberon System
:[[Oberon (operating system)|Oberon System]] is a single user, object-oriented operating system made for the [[Ceres (workstation)|Ceres]] line of [[workstation]]s (processor: [[National Semiconductor]] [[NS32000]]), developed in the later 1980s at [[ETH Zurich]] by [[Niklaus Wirth]] and [[Jürg Gutknecht]]. It is built entirely from modules of the programming language [[Oberon (programming language)|Oberon]].<ref>{{cite report |last1=Wirth |first1=Niklaus |author1-link=Niklaus Wirth |last2=Gutknecht |first2=Jürg |author2-link=Jürg Gutknecht |date=1988 |title=The Oberon System: Report Number 88 |url=http://e-collection.library.ethz.ch/eserv/eth:3180/eth-3180-01.pdf}}</ref> There are two successors of the Oberon System, ETHOS (see above) and, as of 2023 still maintained, an evolution named ''Active Object System'' (AOS),<ref name="AOSthesis">{{Cite thesis |type=PhD |last=Muller |first=Pieter Johannes |date=2002 |title=The active object system design and multiprocessor implementation |url=http://e-collection.library.ethz.ch/eserv/eth:26082/eth-26082-02.pdf |publisher=Swiss Federal Institute of Technology, Zürich ([[ETH Zurich]])}}</ref> then renamed ''Bluebottle'', then renamed ''[[A2 (operating system)|A2]]''.
; OOSMOS
:The Object-Oriented State Machine Operating System (OOSMOS), written in C, promotes object-oriented encapsulation and implements a full table-driven hierarchical state machine architecture. It generates C code directly from state charts drawn with the open source tool [[UMLet]]. OOSMOS also supports a unique feature call 'state threads' which allows a thread of execution per state. OOSMOS operates on a bare board or in cooperation with an existing operating system.
; Phantom OS
:[[Phantom OS]] adheres to a principle where "everything is an object" and eliminates the concept of a file entirely, instead transparently persisting virtual memory to storage.
; ReactOS
:[[ReactOS]] is an open-source operating system intended to be binary compatible with application software and [[device driver]]s made for Microsoft Windows NT versions. Written from scratch, it aims to follow the [[architecture of Windows NT]] designed by Microsoft from the hardware level right through to the application level. This is ''not'' a Linux-based system, and shares ''none'' of the [[Unix|unix architecture]].<ref>{{cite web
 | url = http://reactos.org
 | title = About ReactOS: Object Based
 | first = Klemens
 | last = Friedl
 | publisher = ReactOS Project
 | quote = ReactOS uses an object metaphor that is pervasive throughout the architecture of the system. Not only are all of the things in the UNIX file metaphor viewed as objects by ReactOS, but so are things such as processes and threads, shared memory segments, the global registry database and even access rights.
| access-date = 2017-02-19
}}</ref><ref>Filby, J. "ReactOS: An open-source alternative to NT?." ''IEEE Software'' 16.1 (1999): 35–35.</ref>
; Smalltalk
:[[Smalltalk]] was invented at [[Xerox]] in the 1970s. The Smalltalk system is fully object-oriented and needs very little support by [[BIOS]] and the [[run-time system]].
; Syllable
:[[Syllable Desktop|Syllable]] makes heavy use of [[C++]] and for that reason is often compared to [[BeOS]].
; Symbolics Genera
:[[Genera (operating system)|Genera]] from [[Symbolics]] is an operating system for [[Lisp machine]]s written in [[ZetaLisp]] and Symbolics [[Common Lisp]]. It makes heavy use of [[Flavors (programming language)|Flavors]] (an early object-oriented extension to Lisp) and the [[Common Lisp Object System]] (CLOS). Development began in the mid 70s at MIT.
; Taligent
:[[Taligent]] was an object-oriented operating system project, begun by [[Apple Inc.]] and jointly developed with [[IBM]] in the 1990s. It was later spun off to an IBM subsidiary and transformed from an operating system to a programming environment.

== See also ==
* [[Operating system]]
* [[Object-oriented design]]
* [[Object-oriented programming]]
* [[Plan 9 from Bell Labs]]

== References ==
{{Reflist|2}}

==External links==
{{Commonscat|Object-oriented operating systems}}
*[http://www.sonycsl.co.jp/project/Apertos/ Apertos] {{Webarchive|url=https://web.archive.org/web/20070928175547/http://www.sonycsl.co.jp/project/Apertos/ |date=2007-09-28 }}
*[http://choices.cs.uiuc.edu/ Choices] {{Webarchive|url=https://web.archive.org/web/20060116064949/http://choices.cs.uiuc.edu/ |date=2006-01-16 }}
*[http://www.research.ibm.com/people/d/dfb/hermes.html Hermes], former IBM project
*[https://www.oosmos.com/ OOSMOS]
*[http://obligement.free.fr/articles_traduction/itwsassenrath_en.php Rebol] aspirations to displace the OS with the language environment

{{Operating system}}

[[Category:Object-oriented programming]]
[[Category:Object-oriented operating systems| ]]
[[Category:Operating system technology]]