open/free documentation license comparison

here's an ascii version of the license section my "manual and beyond" RFC paper i'd used as a preparation of my conference talk in frankfurt i tried to analyse the copyright situation and the choice of licenses as i saw it back then (almost half a year ago) and have added a small update: License and Copyright The current phpdoc repository is licensed under the GPL and copyright holders are the members of the PHP Documentation Group as listed on the Manual front page. As the GPL focuses on code and not on documentation content it is not really the right choice for protecting the manual. There has been some discussion on the phpdoc mailing list every once in a while but no conclusion has been reached yet. So i'll try to present some of the licenses that might fit and their goals, pros and cons. License Goals

    Whatever the new license will be, it has to make sure that
    copyright is kept intact and that nobody but the copyright holders
    may change the license, neither in original nor in modified form
    and that the original authors and contributers get the credits
    they deserve. It has not become clear whether commercial
    distribution should be possible or not.

The FreeBSD Documentation License

    The FreeBSD Documentation License is very much like the modified
    BSD license. It does not restrict redistribution and/or
    modification at all as long as the license and copyright notice is
    kept intact.

The Open Content License

    The Open Content License allows modifications as long as the
    license and copyright are kept intact and modified versions are
    clearly marked as such, but it does not permit
    charging for the distribution of the content itself, you may only
    charge for media and for additional services you provide related
    to the content.

The Open Publishing License

    The Open Publishing License (not to be confused with the Open
    Content License) goes more into the details of publishing and
    defines fair use of content. It does, for example, require that
    the original authors have to be printed on the cover if the
    content is published in book form.
    The original license is rather liberal regarding modifications and
    commercial publishing, but there are two license options that can
    be added to deny substantial modifications or commercial
    publishing without special permission.

The GNU Free Documentation License

    This License goes even more into detail as it was the only one of
    those presented here that was created with the help of
    professional lawyers. It tries to define the details of fair use
    similar to the Open Publishing License, but with a slightly
    different focus. It does not prevent modifications or commercial
    distribution as long as copyright and license are kept intact and
    modifications are made available in source form.

Conclusion (sort of)

    IMHO commercial distribution of the PHP documentation should not
    be restricted as the distribution of PHP itself is not restricted
    in that way, too. On the other hand the FreeBSD Documentation
    License, that is very similar to the PHP License, does not really
    solve the issues in which the current GPL lacks. In the spirit of
    the current license the GNU Free  Documentation
    License should be the best choice. All contributions to the manual
    have been made under the GPL, and although the copyright holders
    that the copyright for these contributions has been transfered to
    have the right to change the license for future versions they should
    perhaps stay in the same spirit when changing the license for
    practical reasons. If the final decision regarding commercial
    redistribution goes against me, then the Open Publication License
    including option 'B' should be the best choice for a new manual
    license.

PS: this has been written almost half a year ago now and some things

    have changed since then. we have a new, BSDish Zend Engine license
    and ZendAPI documentation has been bundled with the manual and
    is even about to be merged with it on the source level
    so today i'd rather suggest to just switch to the OPL and use
    the same options as the zendAPI doc