We have opted to use semantic version for release numbers of Adapt products. This page goes some way to explain how they work.

Semantic Versioning uses a three-part version number, represented by: MAJOR.MINOR.PATCH

A major release signifies changes to the API which are not backward-compatible (we call these breaking changes).

• Usually introduces backwards-incompatible, breaking changes.
• Introduces the APIs we intend to support for the foreseeable future.

A minor release add new (but crucially, backward-compatible) API features.

• Includes additions and/or refinements of APIs and subsystems.
• Do not generally change APIs nor introduce backwards-incompatible breaking changes, except where unavoidable.
• Are mostly additive releases.

A patch release represents minor changes and bug fixes which do not change the software's public API/interface.

• Includes bug, performance, and security fixes.
• Do not add nor change public interfaces.
• Do not alter the expected behaviour of a given interface.
• Can correct behaviour if it is out-of-sync with the documentation.

• A plugin's first stable release should have a version number of: 1.0.0
• A subsequent bug-fix should bump the patch version number, resulting in 1.0.1
• A new backward-compatible feature is added, so the minor version is incremented: 1.1.0 (note that the patch number is reset to 0)
• Another bug-fix is added, changing the version to: 1.1.1
• Some breaking changes are introduced, so the major version is incremented, and the minor and patch numbers are reset: 2.0.0

If you want to know more about semantic versioning, check out this page written by @mojombo.

The Node.js community have straightforward guidelines for their release process (upon which we have modelled our own process).