A.6. Package Versioning

PEAR has a very well-defined (and again, de facto standard) versioning scheme for packages. A package version has two components: the version number, and the package stability; you will often see this expressed as 0.2.0-dev or 1.5.1-stable.

The version number consists of three parts expressed in an X.Y.Z format: Major.Minor.Micro. These three parts are incremented as follows:

• Major: when backwards-incompatible changes occur

• Minor: when features are added

• Micro: bug fix (only) releases

In addition to these taxonomies, there are four designated stability monikers:

• dev: totally broken

• alpha: still quite broken

• beta: might be broken

• stable: shouldn’t be broken

The last (stable) is optional in a version number, and is assumed when no other moniker is specified. As a matter of note, there is a fifth state: RC, which stands for Release Candidate—a version with the potential to be a final product, but which may still have a few bugs. RC status can be achieved by setting a beta state and appending RC and a sequential number to the version number, such as 1.0.0RC1.