Development stage
In software development, development stage terminology expresses how far through the development sequence things have progressed and how much further development a product may require.
Alpha
An alpha version or alpha release represents the first version of a computer program or other product, likely to be very unstable but useful for demonstrating internally and to select customers. Some developers refer to this stage as a preview, as a technical preview or as an early access.
Alpha is the first letter in the Greek alphabet.
Beta
The beta version of a product still awaits full debugging or full implementation of all its functionality, but satisfies a majority of the requirements. Beta versions (or just betas) stand at an intermediate step in the full development cycle. Developers release them to a group of beta testers (or, sometimes, to the general public) for a user test. The testers report any bugs that they found, features they would like to see in the final version, etc. When a beta becomes available to the general public it often becomes used almost as widely as the finished product (when developers subsequently complete that product). Usually developers of freeware or open-source betas release them to the general public while proprietary betas go to a relatively small group of testers. Recipients of highly proprietary betas may have to sign a non-disclosure agreement.
Since this is the second major stage in the development cycle, following the alpha stage, it is named after the Greek letter beta, the second letter in the Greek alphabet.
Release candidate
The term release candidate can refer to a final product, ready to release unless fatal bugs emerge. In this stage, the product features all designed functionalities and no known showstopper class bugs. Microsoft Corporation often uses the term release candidate.
Stable/Unstable
In open source programming, version numbers or the terms stable and unstable more commonly distinguish the stage of development. In the Linux kernel, version numbers take the form of three numbers, separated by a decimal point. With regards to the second number, even numbers represent a stable release and odd numbers indicate an unstable release. The practice of using even and odd numbers to indicate the stability of a release has featured in many other open source projects.
See also
