PHP 5 Power Programming

12.3. Release Versioning

This section assumes that you have read the “Version Numbers” section in Chapter 10.

The first rule defines the version number of the first stable release:

• The first stable release of a package must use the version number 1.0.0.

• Releases prior to the first stable release must use a 0.x version number, and must not be stable.

• Backward compatibility may be broken arbitrarily between 0.x releases.

  After the first stable release, some more rules start kicking in:

• Release 1.N must be compatible with 1.M where N > M. For example, 1.3 must be compatible with 1.2.

• Release N.x may break compatibility with M.x where N > M. For example, 3.0 may break compatibility with 2.4.

• New features require that the minor version increases (for example, ...