Editing Software release life cycle (section)

== Stages of development ==

=== Pre-alpha ===
Pre-alpha refers to all activities performed during the software project before formal testing. These activities can include [[requirements analysis]], [[software design]], [[software development]], and [[unit testing]]. In typical [[Open-source software|open source]] development, there are several types of pre-alpha versions. ''Milestone'' versions include specific sets of functions and are released as soon as the feature is complete.{{citation needed|date=April 2023}}

=== Alpha ===
The alpha phase of the release life cycle is the first phase of [[software testing]] (alpha is the first letter of the [[Greek alphabet]], used as the number 1). In this phase, developers generally test the software using [[white-box testing|white-box techniques]]. Additional validation is then performed using [[black-box testing|black-box]] or [[Grey box testing#Grey box testing|gray-box]] techniques, by another testing team. Moving to black-box testing inside the organization is known as ''alpha release''.<ref>{{cite magazine|url=https://www.pcmag.com/encyclopedia_term/0,2542,t=alpha+version&i=37675,00.asp |title=Encyclopedia definition of alpha version |magazine=[[PC Magazine]] |access-date=2011-01-12 |url-status=live |archive-url=https://web.archive.org/web/20110427065905/http://www.pcmag.com/encyclopedia_term/0%2C2542%2Ct%3Dalpha%20version%26i%3D37675%2C00.asp |archive-date=2011-04-27 }}</ref><ref>{{cite web|url=https://video-answer.com/what-is-an-alpha-version-of-a-game/|title= What is an alpha version of a game?|access-date=2022-09-23|archive-url=https://web.archive.org/web/20220923135620/https://video-answer.com/what-is-an-alpha-version-of-a-game/ |archive-date=Sep 23, 2022}}</ref>

Alpha software is not thoroughly tested by the developer before it is released to customers. Alpha software may contain serious errors, and any resulting instability could cause crashes or data loss.<ref>{{cite book |editor-last=Ince |editor-first=Darrel |title=A Dictionary of the Internet |edition=3rd |chapter=Alpha software |date=2013 |publisher=Oxford University Press |isbn=978-0-19-174415-0 |url=https://www.oxfordreference.com/abstract/10.1093/acref/9780191744150.001.0001/acref-9780191744150-e-95?rskey=VLB7Gk&result=2 |access-date=15 July 2019 }}</ref> Alpha software may not contain all of the features that are planned for the final version.<ref>{{cite magazine|title=The Next Generation 1996 Lexicon A to Z|magazine=[[Next Generation (magazine)|Next Generation]]|issue=15 |publisher=[[Imagine Media]]|date=March 1996|page=29|quote=Alpha software generally barely runs and is missing major features like gameplay and complete levels.}}</ref> In general, external availability of alpha software is uncommon for [[proprietary software]], while [[Free and open-source software|open source software]] often has publicly available alpha versions. The alpha phase usually ends with a [[Freeze (software engineering)|feature freeze]], indicating that no more features will be added to the software. At this time, the software is said to be [[#Feature-complete|feature-complete]]. A beta test is carried out following [[acceptance testing]] at the supplier's site (the alpha test) and immediately before the general release of the software as a product.<ref>{{cite book |title=A Dictionary of Computer Science |date=2016 |publisher=Oxford University Press |isbn=978-0-19-968897-5 |page=44 |edition=7th}}</ref>

==== Feature-complete ====
A '''feature-complete''' (FC) version of a piece of [[software]] has all of its planned or primary [[Software feature|features]] implemented but is not yet final due to [[software bug|bugs]], [[software performance|performance]] or [[Software testing|stability]] issues.<ref>{{cite book |last=Cusumano |first=Michael |date=1998 |url=https://archive.org/details/microsoftsecrets00cusu |title=Microsoft Secrets: How the World's Most Powerful Software Company Creates Technology, Shapes Markets, and Manages People |publisher=Free Press |isbn=978-0-684-85531-8 |pages=[https://archive.org/details/microsoftsecrets00cusu/page/202 202–203] |url-access=registration }}</ref> This occurs at the end of alpha testing in [[Software development|development]].

Usually, feature-complete software still has to undergo [[beta testing]] and [[Patch (computing)|bug fixing]], as well as performance or stability enhancement before it can go to [[#Release candidate|release candidate]], and finally [[#Release|gold]] status.

=== Beta<span class="anchor" id="BETA"></span> ===
{{Redirect|Beta test|the 2016 film|Beta Test (film)|the 2021 film|The Beta Test}}
{{See also|Software testing#Beta testing}}

Beta, named after [[Beta|the second letter of the Greek alphabet]], is the software development phase following alpha. A beta phase generally begins when the software is feature-complete but likely to contain several known or unknown bugs.<ref>{{cite magazine |title=The Next Generation 1996 Lexicon A to Z |magazine=[[Next Generation (magazine)|Next Generation]] |issue=15 |publisher=[[Imagine Media]] |date=March 1996 |page=30 |url=https://archive.org/details/nextgen-issue-015/page/n31/mode/2up }}</ref> Software in the beta phase will generally have many more bugs in it than completed software and speed or performance issues, and may still cause crashes or data loss. The focus of beta testing is reducing impacts on users, often incorporating [[usability testing]]. The process of delivering a beta version to the users is called ''beta release'' and is typically the first time that the software is available outside of the organization that developed it. Software beta releases can be either [[#Open and closed beta|open or closed]], depending on whether they are openly available or only available to a limited audience. Beta version software is often useful for demonstrations and previews within an organization and to prospective customers. Some developers refer to this stage as a ''preview'', ''preview release'', ''prototype'', ''technical preview'' or ''technology preview'' (''TP''),<ref>{{cite web | url = https://access.redhat.com/support/offerings/techpreview | title = Technology Preview Features Support Scope | access-date = 2015-03-18 | publisher = [[Red Hat]] }}</ref> or ''[[early access]]''.

''Beta testers'' are people who actively report issues with beta software. They are usually customers or representatives of prospective customers of the organization that develops the software. Beta testers tend to volunteer their services free of charge but often receive versions of the product they test, discounts on the release version, or other incentives.<ref>{{cite news |author1=Amit Mehra |author2=Rajib Lochan Saha |title=Utilizing Public Betas and Free Trials to Launch a Software Product |date=19 June 2017 |journal=Production and Operations Management |volume=27 |issue=11}}</ref><ref>{{cite news |first=Michelle M. |last=Lang |title=Beta Wars |date=17 May 2004 |journal=Design News |volume=59 |issue=7 }}</ref>

==== Perpetual beta ====
{{Main|Perpetual beta}}

Some software is kept in so-called ''perpetual beta'', where new features are continually added to the software without establishing a final "stable" release. As the [[Internet]] has facilitated the rapid and inexpensive distribution of software, companies have begun to take a looser approach to the use of the word ''beta''.<ref>{{cite web |url=https://tidbits.com/1996/05/13/waiting-with-betad-breath/ |title=Waiting with Beta'd Breath ''TidBITS'' #328 (May 13, 1996) |date=13 May 1996 |archive-url=https://web.archive.org/web/20221206214914/https://tidbits.com/1996/05/13/waiting-with-betad-breath/ |archive-date=2022-12-06 }}</ref>

==== Open and closed beta ====
Developers may release either a ''closed beta'', or an ''open beta''; closed beta versions are released to a restricted group of individuals for a user test by invitation, while open beta testers are from a larger group, or anyone interested. Private beta could be suitable for the software that is capable of delivering value but is not ready to be used by everyone either due to scaling issues, lack of documentation or still missing vital features. The testers report any bugs that they find, and sometimes suggest additional features they think should be available in the final version.

Open betas serve the dual purpose of demonstrating a product to potential consumers, and testing among a wide user base is likely to bring to light obscure errors that a much smaller testing team might not find.{{citation needed|date=November 2024}}

=== Release candidate ===
[[File:Microsoft windows 2000 server rc2 media.jpg|thumb|upright|Microsoft Windows 2000 Server Release Candidate 2 media.]]

A ''release candidate'' (''RC''), also known as gamma testing or "going silver", is a beta version with the potential to be a stable product, which is ready to release unless significant [[software bug|bugs]] emerge. In this stage of product stabilization, all product features have been designed, coded, and tested through one or more beta cycles with no known showstopper-class bugs. A release is called ''code complete'' when the development team agrees that no entirely new source code will be added to this release. There could still be source code changes to fix defects, changes to documentation and data files, and peripheral code for test cases or utilities.{{citation needed|date=November 2024}}

=== Stable release ===
Also called ''production release'', the ''stable release'' is the last ''release candidate'' (''RC'') which has passed all stages of verification and tests. Any known remaining bugs are considered acceptable. This release goes to [[Deployment environment#Production|production]].

Some software products (e.g. [[Linux distribution]]s like [[Debian#Branches|Debian]]) also have ''[[long-term support]]'' (''LTS'') releases which are based on full releases that have already been tried and tested and receive only security updates.{{citation needed|date=November 2024}}