X.Org and XFree86 Version Numbering Schemes

                              Abstract

    X.Org has adopted the same basic numbering scheme used by the
    XFree86 Project, Inc. for their releases. The actual numbers
   are different, but the basic scheme is the same. This document
     reflects the policy that X.Org uses. The version numbering
       schemes used by XFree86 have changed from time to time.
           _______________________________________________

   Table of Contents
   Releases, Development Streams and Branches
   Current (new) Version Numbering Scheme
   Finding the X.Org X Server Version From a Client

Releases, Development Streams and Branches

   As of the release of version X11R6.7 in March 2004, X.Org has
   three release branches. First is the trunk of the CVS
   repository. This is the main development stream, where all new
   work and work for future releases is done.

   Second is the stable bugfix branch for the latest full release
   (7.1.0). It is created around the time of the release. The
   branch for the current release is called "XORG-7_1-branch".
   Fixes for bugs found in the release will be added to this
   branch (as well as the trunk), and updates to this release (if
   any) will be cut from this branch. Similar stable branches are
   present for previous full releases.

   The X.Org Foundation is planning to make full releases from the
   main development stream at regular intervals in the 6-12 month
   range. The feature freezes for these releases will usually be
   2-3 months before the release dates. This general plan is a
   goal, not a binding commitment. The actual release intervals
   and dates will depend to a large degree on the resource
   available to X.Org. Full releases consist of full source code
   tarballs, plus full binary distributions for a range of
   supported platforms. Update/bugfix releases will be made on an
   as-required basis, depending also on the availability of
   resources, and will generally be limited to serious bug and
   security fixes. New features will not usually be added in
   update releases. Update/bugfix releases will not be full
   releases, and will consist of source code patches, plus binary
   updates to be layered on top of the previous full release.

   The next full release will be version 7.2.

   Aside from actual releases, snapshots of the active release
   branches are tagged in the CVS repository from time to time.
   Each such snapshot has an identifiable version number.
     __________________________________________________________

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.
     __________________________________________________________

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.
     __________________________________________________________

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.
     __________________________________________________________

Finding the X.Org X Server Version From a Client

   The X.Org X servers report a VendorRelease value that matches
   the X.Org version number. There have been some cases of
   releases where this value wasn't set correctly. The rules for
   interpreting this value as well as the known exceptions are
   outlined here.

   For post-6.7.0 development and release versions using the new
   numbering scheme, the VendorRelease value is MMmmPPsss. That
   is, version M.m.P.s has VendorRelease set to
   M * 10000000 + m * 100000 + P * 1000 + s.

   The following is a code fragment taken from xdpyinfo.c that
   shows how the VendorRelease information can be interpreted.

    if (strstr(ServerVendor(dpy), "X.Org")) {
        int vendrel = VendorRelease(dpy);

        printf("X.Org version: ");
        printf("%d.%d.%d", vendrel / 10000000,
               (vendrel /   100000) % 100,
               (vendrel /     1000) % 100);
        if (vendrel % 1000) {
            printf(".%d", vendrel % 1000);
        }
    }
