DRAFT FAQ: Free vs. Open

Matthew Flaschen matthew.flaschen at gatech.edu
Fri Jan 11 02:36:11 UTC 2008

Philippe Verdy wrote:
> Well, this means that "open source" is a weakened definition of "free
> software", but I'm not sure that this really applies in practice, because
> most open source softwares are also free software (the reverse is not
> necessarily true).

What free software licenses fail to comply with the OSD?

> But are there cases where some "free" content that is considered by some as
> not being "open source". A known example is the GNU FDL licence (used by
> Wikimedia wiki projects) that is not directly compatible with GPL and open
> source, but still qualified as being "free".

This is not a software license, and is currently beyond the scope of
OSI.  Moreover, there is no such thing as "compatible with [...] open

> Let's stay away from the philosophic background of the FSF, this is their
> opinion (possibly shared volantrily by others)

If we're going to discuss the differences between OSI and the FSF, it is
foolish to ignore their respective philosophies.

> (excluding also the "Preamble" which is not binding, even though it is
> widely advertised, it is not a required part of the FSF licences, including
> in "verbatim" copies of the licence, a Preamble that you can freely drop if
> it does not reflect your opinion).

The preamble is not legally binding (it may be advisory), but you *can
not* drop it.  If you drop the preamble, you are infringing copyright on
both the license and any software you're distributing with it.

See http://www.fsf.org/licensing/licenses/gpl-faq.html#GPLOmitPreamble,
though it is also clear from the license text itself.

Matt Flaschen

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