Release candidate
The term release candidate refers 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. At this phase the product is usually code complete.
Microsoft Corporation often uses the term release candidate. Other terms include gamma (and occasionally also delta, and perhaps even more Greek letters) for versions that are substantially complete, but still under test, and omega for final testing of versions that are believed to be bug-free, and may go into production at any time. Gamma, delta, and omega are, respectively, the third, fourth, and last letters of the Greek alphabet. 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. Often, beta testers, if privately selected, will be billed for using the release candidate as though it were a finished product.
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.
Gold/general availability release
The gold or general availability release version of a product is the final version of a particular product. It is typically almost identical to the final release candidate, with only last-minute bugs fixed. A gold 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 gold” means that the code has been completed and “is being mass-produced and will be for sale soon.” Other terms for the version include gold master, gold release, or gold build.
The term gold anecdotally refers to the use of “gold master disc” which was commonly used to send the final version to manufacturers who use it to create the mass-produced retail copies. It may in this context be a hold-over from music production. In some cases, however, the master disc is still actually made of gold, for both aesthetic appeal and resistance to corrosion.
Microsoft and others use the term “release to manufacturing” (RTM) to refer to this version (for commercial products, like Windows XP, as in, “Build 2600 is the Windows XP RTM release”), and “release to Web” (RTW) for freely downloadable products..
Development stage - Wikipedia, the free encyclopedia