View source for Multi-user software

{{Short description|Type of computer software}}
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{{redirect|Single user|a product designed for one-time use|Single use}}
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'''Multi-user software''' is [[software|computer software]] that allows access by multiple [[User (computing)|user]]s of a [[computer]].<ref>{{Cite conference |last1=Red |first1=Edward |last2=Jensen |first2=Gregory |last3=French |first3=David |last4=Weerakoon |first4=Prasad |date=10 October 2011 |title=Multi-User Architectures for Computer-Aided Engineering Collaboration |conference=2011 17th International Conference on Concurrent Enterprising, ICE 2011|url=https://www.researchgate.net/publication/252050570 |access-date=6 October 2022 |website=ResearchGate}}</ref> [[Time-sharing]] systems are multi-user systems. Most [[batch processing]] systems for [[mainframe computer]]s may also be considered "multi-user", to avoid leaving the [[central processing unit|CPU]] idle while it waits for [[input/output|I/O]] operations to complete. However, the term "[[computer multitasking|multitasking]]" is more common in this context.

An example is a [[Unix]] or [[Unix-like]] system where multiple remote users have access (such as via a [[serial port]] or [[Secure Shell]]) to the [[Unix shell]] prompt at the same time. Another example uses multiple [[X Window System|X Window]] sessions spread across multiple terminals powered by a single machine – this is an example of the use of [[thin client]]. Similar functions were also available in a variety of non-Unix-like operating systems, such as [[Multics]], [[VM/CMS]], [[OpenVMS]], [[MP/M]], [[Concurrent CP/M]], [[Concurrent DOS]], [[FlexOS]], [[Multiuser DOS]], [[REAL/32]], [[OASIS (operating system)|OASIS]], [[THEOS]], [[PC-MOS]], [[TSX-32]] and [[VM/386]].

Some multi-user operating systems such as [[Windows]] versions from the [[Windows NT]] family support simultaneous access by multiple users (for example, via [[Remote Desktop Connection]]) as well as the ability for a user to disconnect from a local session while leaving processes running (doing work on their behalf) while another user logs into and uses the system. The operating system provides isolation of each user's processes from other users, while enabling them to execute concurrently{{dubious|date=July 2014}}.

[[Management systems]] are implicitly designed to be used by multiple users, typically at least one [[system administrator]] or [[system operator]], and an [[end-user (computer science)|end-user]] community.

The complementary term, '''single-user''', is most commonly used when talking about an operating system being usable only by one person at a time, or in reference to a single-user [[software license agreement]].  Multi-user operating systems such as Unix sometimes have a [[single user mode]] or [[runlevel]] available for emergency maintenance. Examples of single-user operating systems include [[MS-DOS]], [[OS/2]] and [[Classic Mac OS]].

== See also ==
* [[AT Multiuser System]]
* [[Multiseat configuration|Multiseat]]
* [[Multiuser DOS Federation]] (MDOS)

==References==
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== External links ==
* [http://www.microsoft.com/technet/interopmigration/unix/sfu/intrxtse.mspx Interix in a Multi-User Windows TSE Environment] paper about the [[Unix]] multi-user model and [[MS-Windows]] NT [[Terminal Services|TSE]]

[[Category:Operating system technology]]