                  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

   [1]Releases, Development Streams and Branches

   [2]Current (new) Version Numbering Scheme

   [3]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);
           }
       }



References

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