Software release life cycle

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 development, there are several types of pre-alpha versions. Software versions include specific sets of functions and are released as soon as the feature is complete.^{[citation needed]}

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 techniques. Additional validation is then performed using black-box or gray-box techniques, by another testing team. Moving to black-box testing inside the organization is known as alpha release.^[1][2]

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.^[3] Alpha software may not contain all of the features that are planned for the final version.^[4] In general, external availability of alpha software is uncommon for proprietary software, while open source software often has publicly available alpha versions. The alpha phase usually ends with a feature freeze, indicating that no more features will be added to the software. At this time, the software is said to be 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.^[5]

Beta

Beta, named after 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.^[7] 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 the organization that developed it. Software beta releases can be either 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).^[8]

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.^[9][10]

Release candidate

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 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.^[12]

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 production.

Some software products (e.g. Linux distributions like 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.^{[13][14][15][unreliable source][16][unreliable source]}

Release to manufacturing (RTM)

The term "release to manufacturing" (RTM), also known as "going gold", is a term used when a software product is ready to be delivered. This build may be digitally signed, allowing the end user to verify the integrity and authenticity of the software purchase. The RTM build is known as the "gold master" or GM^[18] is sent for mass duplication or disc replication if applicable. The terminology is taken from the audio record-making industry, specifically the process of mastering. RTM precedes general availability (GA) when the product is released to the public. A golden master build (GM) is typically the final build of a piece of software in the beta stages for developers. Typically, for iOS, it is the final build before a major release, however, there have been a few exceptions.

RTM is typically used in certain retail mass-production software contexts—as opposed to a specialized software production or project in a commercial or government production and distribution—where the software is sold as part of a bundle in a related computer hardware sale and typically where the software and related hardware is ultimately to be available and sold on mass/public basis at retail stores to indicate that the software has met a defined quality level and is ready for mass retail distribution. RTM could also mean in other contexts that the software has been delivered or released to a client or customer for installation or distribution to the related hardware end user computers or machines. The term does not define the delivery mechanism or volume; it only states that the quality is sufficient for mass distribution. The deliverable from the engineering organization is frequently in the form of a golden master media used for duplication or to produce the image for the web.

General availability (GA)

General availability (GA) is the marketing stage at which all necessary commercialization activities have been completed and a software product is available for purchase, depending, however, on language, region, and electronic vs. media availability.^[19] Commercialization activities could include security and compliance tests, as well as localization and worldwide availability. The time between RTM and GA can take from days to months before a generally available release can be declared, due to the time needed to complete all commercialization activities required by GA. At this stage, the software has "gone live".

Release to the Web (RTW)

Release to the Web (RTW) or Web release is a means of software delivery that utilizes the Internet for distribution. No physical media are produced in this type of release mechanism by the manufacturer. Web releases have become more common as Internet usage has grown.^[20]

End-of-life

When software is no longer sold or supported, the product is said to have reached end-of-life, to be discontinued, retired, deprecated, abandoned, or obsolete, but user loyalty may continue its existence for some time, even long after its platform is obsolete—e.g., the Common Desktop Environment^[23] and Sinclair ZX Spectrum.^[24]

After the end-of-life date, the developer will usually not implement any new features, fix existing defects, bugs, or vulnerabilities (whether known before that date or not), or provide any support for the product. If the developer wishes, they may release the source code, so that the platform may be maintained by volunteers.