                      XFree86 Version Numbering Schemes

                          The XFree86 Project, Inc

                               16 January 2002

                                  Abstract

     The version numbering schemes used by XFree86 have changed from
     time to time.  The schemes used since version 3.3 are explained
     here.

1.  Releases, Development Streams and Branches

As of the release of version 4.0.2 in December 2000, XFree86 has three
release branches.  First is 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 (4.2.0).  It
is created around the time of the release.  The branch for this one is called
"xf-4_2-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.

Finally there is the 3.3.x legacy branch, which is called "xf-3_3-branch".
While this branch is not actively being maintained, it does include some
important post-3.3.6 bug fixes and security updates.  Relevant security
updates in particular are usually back-ported to this branch.

XFree86 is planning to make full releases from the main development stream
approximately every six months, in late May and November of each year.  The
feature freezes for these releases will be 1 April and 1 October respec-
tively.  These are target dates, not a binding commitment.  How effectively
these dates can be met will depend to a large degree on the resource avail-
able to XFree86.  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 avail-
ability of resources.  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 4.3.0, tentatively scheduled for late
May 2002.  There is no scheduled update release.  If there is one, the ver-
sion will be 4.2.1.

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.

2.  Current (new) Version Numbering Scheme

Starting with the main development branch after 4.0.2, the XFree86 versions
are numbered according to the scheme outlined here.  Both the 4.0.2 stable
branch and the 3.3.x legacy branch continue to use the previous scheme, which
is outlined in the sections below.

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 snap-
shot.  The CVS tag for snapshots is "xf-M_m_P_s".  When the development
branch enters feature freeze, the snapshot number may be bumped to 900, and a
stable branch may be created for the next full release.  The branch is called
"xf-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 4.1.0:

      4.0.99.1
            The first snapshot of the pre-4.1 development branch.

      4.0.99.23
            The twenty-third snapshot of the pre-4.1 development branch.

      4.0.99.900
            The start of the 4.1 feature freeze, which marks the creation of
            the "xf-4_1-branch" branch.  That branch is the "stable" branch
            for the 4.1.x releases.

      4.0.99.903
            The third 4.1.0 release candidate.

      4.1.0
            The 4.1.0 release.

      4.1.99.1
            The first pre-4.2 development snapshot, which  is the first main
            branch snapshot after creating the 4.1 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.  All snap-
shots on this branch are considered "release candidates", so the first is
indicated by setting s to 901.  The snapshot number is then incremented for
each subsequent release candidate until the update release if finalised.  The
patch level value (P) is incremented for each update release.

Here's an example which shows the version number sequence for the 4.1.x sta-
ble branch.

      4.0.99.900
            The start of the 4.1 feature freeze, which marks the creation of
            the "xf-4_1-branch" branch.  That branch is the "stable" branch
            for the 4.1.x releases.

      4.0.99.903
            The third 4.1.0 release candidate.

      4.1.0
            The 4.1.0 release.

      4.1.0.901
            The first pre 4.1.1 snapshot.

      4.1.0.903
            The third pre 4.1.1 snapshot, also known as the third 4.1.1
            release candidate.

      4.1.1
            The 4.1.1 release.

      4.1.1.901
            The first pre 4.1.2 snapshot.

      4.1.2
            The 4.1.2 release.

3.  Version Numbering Scheme for XFree86 4.0.x.

The version numbering format for XFree86 4.0.x releases is M.m.nx, where M is
the major version number (4), m is the minor version number (0), n is the
sub-minor version number, and x is a letter.  Full release versions up to and
including 4.0.2 were 4.0, 4.0.1, and 4.0.2.  Between-release snapshots are
indicated by including x, a lower case letter.  For example, the first
post-4.0.1 snapshot was 4.0.1a.  Release candidates have been indicated by
setting x to a one or two letter combination with the first letter being "Z".
For example, 4.0.1Z was the first 4.0.2 release candidate.

The next 4.0.x release will be an update release, not a full release.  These
update releases will be indicated by incrementing the sub-minor version num-
ber.  So, the first post-4.0.2 update release will be 4.0.3.  Between-release
snapshots will continue to be indicated with a lower case letter, so the
first pre-4.0.3 snapshot will be 4.0.2a.

The following example illustrates the release sequence from 4.0 through to
the post-4.0.2 update releases.

      4.0
            The 4.0 release.

      4.0a
            The first post-4.0 development snapshot.

      4.0f
            The sixth post-4.0 development snapshot.

      4.0Z
            The 4.0.1 release candidate.

      4.0.1
            The 4.0.1 release.

      4.0.1a
            The first post-4.0.1 development snapshot.

      4.0.1f
            The sixth post-4.0.1 development snapshot.

      4.0Z
            The first 4.0.2 release candidate.

      4.0Zb
            The third 4.0.2 release candidate.

      4.0.2
            The 4.0.2 release.

      4.0.2a
            The first pre-4.0.3 snapshot/release candidate.

      4.0.2c
            The third pre-4.0.3 snapshot/release candidate.

      4.0.3
            The 4.0.3 update release.

      4.0.3a
            The first pre-4.0.4 snapshot/release candidate.

      4.0.4
            The 4.0.4 update release.

4.  Pre-4.0 Development Versions

This section is included mostly for historical reasons.

The development leading up to 4.0 started from version 3.2A, but much of it
happened on a separate development branch.  The "new design" work on that
development branch was first folded into the main development branch at ver-
sion 3.9N.  Up until the XFree86 CVS was made publicly available, all ver-
sions containing one or more letters were internal development snapshots.
The internal development snapshots continued through the following sequence:
3.9N, 3.9Na, ..., 3.9Nz, 3.9P, 3.9Pa, ..., 3.9Py, 3.9.15, 3.9.15a, ...,
3.9.16, 3.9.16a, ..., 3.9.17, 3.9.17a, ..., 3.9.18, 3.9.18a, ..., 4.0.  The
3.9.15, 3.9.16, etc versions were public pre-4.0 beta releases.

5.  Version Numbering Scheme for XFree86 3.3.x.

The version numbering format for XFree86 3.3.x releases is M.m.nx, where M is
the major version number (3), m is the minor version number (3), n is the
sub-minor version number, and x is a letter.  Between-release snapshots are
indicated by including x, a lower case letter.  An exception to this scheme
was the 3.3.3.1 release, which was an update to the 3.3.3 release.

      3.3
            The 3.3 release.

      3.3a
            The first post-3.3 development snapshot.

      3.3.1
            The 3.3.1 release.

      3.3.1a
            The first post-3.3.1 development snapshot.

      3.3.2
            The 3.3.2 release.

      3.3.2a
            The first post-3.3.2 development snapshot.

      3.3.3
            The 3.3.3 release.

      3.3.3a
            The first post-3.3.3 development snapshot.

      3.3.3.1
            The 3.3.3.1 release.

      3.3.3.1a
            The first post-3.3.3.1 development snapshot.

      3.3.4
            The 3.3.4 release.

      3.3.4a
            The first post-3.3.4 snapshot.

      3.3.5
            The 3.3.5 release.

      3.3.5a
            The first post-3.3.5 snapshot.

      3.3.6
            The 3.3.6 release.

      3.3.6a
            The first post-3.3.6 snapshot.

6.  Finding the XFree86 X Server Version From a Client

The XFree86 X servers report a VendorRelease value that matches the XFree86
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 3.3.x versions, the VendorRelease value is Mmnp.  That is, version
M.m.n.p has VendorRelease set to M * 1000 + m * 100 + n * 10 + p.  Exceptions
to this are:  The value wasn't incremented for the 3.3.3.1 release, and for
the 3.3.4 and 3.3.5 releases the value was incorrectly set to Mmn
(M * 100 + m * 10 + n).  This was corrected for the 3.3.6 release.

For versions 3.9.15 to 4.0.x, the VendorRelease value is Mmnn.  That is, ver-
sion M.m.n has VendorRelease set to M * 1000 + m * 100 + n.  There have been
no exceptions to this rule.

For post-4.0.2 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.  Note: 4.0.3
and any other 4.0.x releases will continue with the Mmnn scheme.

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

         if (strstr(ServerVendor(dpy), "XFree86")) {
             int vendrel = VendorRelease(dpy);

             printf("XFree86 version: ");
             if (vendrel < 336) {
                 /*
                  * vendrel was set incorrectly for 3.3.4 and 3.3.5, so handle
                  * those cases here.
                  */
                 printf("%d.%d.%d", vendrel / 100,
                                   (vendrel / 10) % 10,
                                    vendrel       % 10);
             } else if (vendrel < 3900) {
                 /* 3.3.x versions, other than the exceptions handled above */
                 printf("%d.%d", vendrel / 1000,
                                (vendrel /  100) % 10);
                 if (((vendrel / 10) % 10) || (vendrel % 10)) {
                     printf(".%d", (vendrel / 10) % 10);
                     if (vendrel % 10) {
                         printf(".%d", vendrel % 10);
                     }
                 }
             } else if (vendrel < 40000000) {
                 /* 4.0.x versions */
                 printf("%d.%d", vendrel / 1000,
                                (vendrel /   10) % 10);
                 if (vendrel % 10) {
                     printf(".%d", vendrel % 10);
                 }
             } else {
                 /* post-4.0.x */
                 printf("%d.%d.%d", vendrel / 10000000,
                                   (vendrel /   100000) % 100,
                                   (vendrel /     1000) % 100);
                 if (vendrel % 1000) {
                     printf(".%d", vendrel % 1000);
                 }
             }
         }

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