2. Current (new) Version Numbering Scheme

Starting with the main development branch after X11R6.7, the X.Org versions are numbered according to the scheme outlined here.

The version numbering format is M.m.P.s, where M is the major version number, m is the minor version number, P is the patch level, and s is the snapshot number. Full releases have P set to zero, and it is incremented for each subsequent bug fix release on the post-release stable branch. The snapshot number s is present only for between-release snapshots of the development and stable branches.

2.1. Development Branch

Immediately after forming a release stable branch, the patch level number for the main development branch is bumped to 99, and the snapshot number is reset. The snapshot number is incremented for each tagged development snapshot. The CVS tag for snapshots is "XORG-M_m_P_s". When the development branch enters feature freeze, the snapshot number is bumped to 900. A stable branch may be created for the next full release at any time after the feature freeze. When it is, the branch is called "XORG-M_m-branch". The snapshot number is incremented from there until the release is finalised. Each of these snapshots is a "release candidate". When the release is finalised, the minor version is incremented, the patch level is set to zero, and the snapshot number removed.

Here's an example which shows the version number sequence for the development leading up to version 6.8:

6.7.99.1

The first snapshot of the pre-6.8 development branch.

6.7.99.23

The twenty-third snapshot of the pre-6.8 development branch.

6.7.99.900

The start of the 6.8 feature freeze.

6.7.99.903

The third 6.8 release candidate.

6.8.0

The 6.8 release.

6.8.99.1

The first pre-6.9 development snapshot, which is the first main branch snapshot after creating the 6.8 stable branch.

2.2. Stable Branch

After a full release, the stable branch for the release will be maintained with bug fixes and important updates until the next full release. Any snapshots on this branch are considered "release candidates", which is indicated by setting s to a number above 900. The snapshot number is incremented for each release candidate until the update release is finalised. The patch level value (P) is incremented for each update release.

Here's an example which shows a version number sequence for a 6.8.x stable branch:

6.8.0

The 6.8 release.

6.8.0.901

The first pre 6.8.1 snapshot.

6.8.0.903

The third pre 6.8.1 snapshot, also known as the third 6.8.1 release candidate.

6.8.1

The 6.8.1 release.

6.8.1.901

The first pre 6.8.2 snapshot.

6.8.2

The 6.8.2 release.