BitKeeper license

Dear LWN Editors,

I trust you are aware of the recent discussion around the BitKeeper
license on the kernel mailing list[1].  (Also see the thread[2] on
debian-devel.)  Tom Gall noticed that the gratis BitKeeper license has
the following clause in Section 3:

    (d) Notwithstanding any other terms in this License, this
        License is not available to You if You and/or your
        employer develop, produce, sell, and/or resell a
        product which contains substantially similar capabil-
        ities of the BitKeeper Software, or, in the reason-
        able opinion of BitMover, competes with the BitKeeper
        Software.

Larry McVoy has specifically stated[3] that Ben Collins (a developer
of Subversion, a replacement for CVS, and also a part-time kernel
developer) has no gratis license for BitKeeper as a result of this
clause.  Elsewhere in the thread, he asserted[4] that if certain
(planned[5]) features were added to the kernel, the gratis license
would terminate (and, therefore, all kernel developers using BK would
have to scramble to find alternatives).  In light of these
developments, I hope that you will reconsider your position from 1999:
In a front page article, you suggested[6] that the restrictions in the
BK license were not very severe:

    The interesting thing is that, on a list for kernel hackers who
    intend to use the system, nobody really cares all that much. Even
    members of the OSI board have posted there, saying that the
    license is a good one, and that the lack of the "Open Source"
    designation should not be a problem. BitKeeper is free enough for
    that crowd, and they tend to be pretty fussy on these things.

The license has changed since you wrote this; in particular, the
clause above was apparently added about 6 months ago.  However, there
is another clause in the BK license requiring you to use the latest
version of the license.  Here we see that BitKeeper is, in fact, quite
far from open source or free software: The non-free terms of the
license are being used to exert leverage, in exactly the same way that
(say) Microsoft exerts pressure on OEMs.

Larry McVoy and the BitMover corporation are, of course, free to
license BitKeeper however they want.  But I would urge free software
developers to think carefully before relying on the tools of a vendor
that is so willing to change their license terms to satisfy personal
aims.

Sincerely yours,
	Dylan Thurston

[1] http://www.uwsg.indiana.edu/hypermail/linux/kernel/0210.0/1496.html
[2] http://lists.debian.org/debian-devel/2002/debian-devel-200210/msg00245.html
    (Oddly, the original message from Branden Robinson seems to be
    missing from the archive.)
[3] http://www.uwsg.indiana.edu/hypermail/linux/kernel/0210.0/1725.html
[4] http://www.uwsg.indiana.edu/hypermail/linux/kernel/0210.0/2096.html
[5] http://www.uwsg.indiana.edu/hypermail/linux/kernel/0210.0/2133.html
[6] http://old.lwn.net/1999/features/BitKeeper.php3

(Please feel free to include this on the Letters to the Editor page.)