Software release life cycle

A software release is the distribution of software code, documentation, and support materials. The software release life cycle is composed of discrete phases that describe the software's maturity as it advances from planning and development to release and support phases.

Development

Pre-alpha

Pre-alpha refers to all activities performed during the software project prior to 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. Milestone versions include specific sets of functions and are released as soon as the functionality is complete.

Alpha

The alpha phase of the release life cycle is the first phase to begin software testing (alpha is the first letter of the ancient 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.
Alpha software can be unstable and could cause crashes or data loss. The exception to this is when the alpha is available publicly (such as a pre-order bonus), in which developers normally push for stability so that their testers can test properly. External availability of alpha software is uncommon.
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.

Beta

Beta is the software development phase following alpha (beta is the second letter of the ancient Greek alphabet, used as the number 2. It is not nowadays usual to speak of a later gamma test). It generally begins when the software is feature complete. The focus of beta testing is reducing impacts to users, often incorporating usability testing. The process of delivering a beta version to the users is called beta release and this is typically the first time that the software is available outside of the organization that developed it.
The users of a beta version are called beta testers. They are usually customers or prospective customers of the organization that develops the software, willing to test the software without charge, often receiving the final software free of charge or for a reduced price.
Beta version software is often useful for demonstrations and previews within an organisation and to prospective customers. Some developers refer to this stage as a preview, prototype, technical preview (TP), or early access.
Some software is kept in perpetual beta.

Open and closed beta

Developers release either a closed beta or an open beta; closed beta versions are released to a select group of individuals for a user test, while open betas are to a larger community group, sometimes to anyone interested. The testers report any bugs that they find, and sometimes suggest additional features they think should be available in the final version. Examples of a major public beta test are:

• In September 2000 a boxed version of Apple Inc.'s Mac OS X Public Beta operating system was released.
• Microsoft's release of community technology previews (CTPs) for Windows Vista in January 2005.

Open betas serve the dual purpose of demonstrating a product to potential consumers, and testing among an extremely wide user base likely to bring to light obscure errors that a much smaller testing team may not find.
Though, online Free-to-play (F2P) games have developed a trend to use Open Beta to lure customers with an intent to profit off customers in a same aspect if such F2P were a final product.Many such games can be locked in Open Beta for years before going final for example Conquer Online. Open Beta in F2P is coming a more meaningless concept for testing compared to a powerful business model for profit with Cash shop items either in game or on official website. Such purchases can only be done by exchanging real money for Item mall currency. Such currency exchange varies from F2P to F2P.

Release candidate

The term release candidate (RC) refers to a version with potential to be a final product, ready to release unless fatal 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 bug.
Apple Inc. uses the term "golden master" for its release candidates, and the final golden master is used as the general availability release. Other Greek letters, such as gamma and delta, are sometimes used to indicate versions that are substantially complete, but still undergoing testing, with omega or zenith used to indicate final testing versions that are believed to be relatively bug-free, ready for production.
A release is called code complete when the development team agrees that no entirely new source code will be added to this release. There may still be source code changes to fix defects. There may still be changes to documentation and data files, and to the code for test cases or utilities. New code may be added in a future release.

Origin of alpha and beta terminology

The term beta test comes from an IBM convention, dating back to punched card tabulating and sorting machines. Hardware first went through an alpha test for preliminary functionality and small scale manufacturing feasibility. Then came a beta test, to verify that the hardware correctly performed the intended functions and could be manufactured at scale. Ultimately, a gamma test was performed to verify safety.
When IBM began testing software, it used the same terminology as it had for hardware. As other companies began developing their own software, they adopted and kept the same terminology

Release

RTM

The term "release to manufacturing" or "release to marketing" (both abbreviated RTM, initials also commonly used for the quite different "return to manufacturer" of faulty goods)—also known as "going gold"—is a term used when software is ready for or has been delivered or provided to the customer. It 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 gold master CD used for duplication or to produce the image for the web.
RTM precedes general availability (GA) when the product is released to the public.

General availability

General availability or general acceptance (GA) is the point where all necessary commercialization activities have been completed and the software has been made available to the general market either via the web or physical media. Another term with a meaning almost identical to GA is first customer shipment (FCS). Some companies (such as Sun Microsystems and Cisco) use FCS to describe a software version that has been shipped for revenue.
Commercialization activities could include but are not limited to the availability of media world wide via dispersed distribution centers, marketing collateral is completed and available in as many languages as deemed necessary for the target market, the finishing of security and compliance tests, etc. The time between RTM and GA can be from a week to months in some cases before a generally available release can be declared because of the time needed to complete all commercialization activities required by GA.
It is also at this stage that the software is considered to have "gone live". The production, live version is the final version of a particular product. A live release is considered to be very stable and relatively bug-free with a quality suitable for wide distribution and use by end users. In commercial software releases, this version may also be signed (used to allow end-users to verify that code has not been modified since the release). The expression that a software product "has gone live" means that the code has been completed and is ready for distribution. Other terms for the live version include live master, live release, and live build.
In some areas of software development it is at this stage that the release is referred to as a gold release; this seems to be confined mainly to game software.
Some release versions might be classified as a long term support (LTS) release, which should guarantee the ability to upgrade to the next LTS release and will be supported/updated/patched for a longer time than a non-LTS release.

 Service release

During its supported lifetime, software is sometimes subjected to service releases, or service packs. As a well used example, Microsoft's Windows XP has currently had 3 major Service Packs.
Such service releases contain a collection of updates, fixes and/or enhancements, delivered in the form of a single installable package. They may also contain entirely new features.
Certain software is released with the expectation of regular support. Classes of software that generally involve protracted support as the norm include anti-virus suites and massively multiplayer online games.

 End-of-life

When software is no longer sold or supported, the product is said to have reached end-of-life.

Impact of the World Wide Web

As the Internet has allowed for rapid and inexpensive distribution of software, companies have begun to take a more loose approach to use of the word "beta"^. Netscape Communications was infamous for releasing alpha level versions of its Netscape web browser to the public and calling them "beta" releases. In February 2005, ZDNet published an article about the recent phenomenon of a beta version often staying for years and being used as if it were in production level. It noted that Gmail and Google News, for example, had been in beta for a long period of time and were not expected to drop the beta status despite the fact that they were widely used; however, Google News did leave beta in January 2006, followed by Google Apps, including Gmail, in July 2009. This technique may also allow a developer to delay offering full support and/or responsibility for remaining issues. In the context of Web 2.0, people even talk of perpetual betas to signify that some software is meant to stay in beta state. Also, "beta" is sometimes used to indicate something more like a release candidate, or as a form of time limited demo, or marketing technique.
Some users disparagingly refer to release candidates and even final "point oh" releases as "gamma test" software, suggesting that the developer has chosen to use its customers to test software that is not truly ready for general release. Beta testers, if privately selected, will often be credited for using the release candidate as though it were a finished product.

Web release

A 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. This is sometimes also referred to as release to web (RTW).