The Open Source Definition
Open source doesn't just mean access to the source code. The
distribution terms of open-source software must comply with the
following criteria:
1. Free Redistribution
The license may not restrict any party from selling or giving away the
software as a component of an aggregate software distribution containing
programs from several different sources. The license may not require a
royalty or other fee for such sale.
(rationale)
2. Source Code
The program must include source code, and must allow distribution in
source code as well as compiled form. Where some form of a product is
not distributed with source code, there must be a well-publicized
means of obtaining the source code for no more than a reasonable
reproduction cost -- preferably, downloading via the Internet without
charge. The source code must be the preferred form in which a
programmer would modify the program. Deliberately obfuscated source
code is not allowed. Intermediate forms such as the output of a
preprocessor or translator are not allowed. (rationale)
3. Derived Works
The license must allow modifications and derived works, and must allow
them to be distributed under the same terms as the license of the original
software.
(rationale)
4. Integrity of The Author's Source Code.
The license may restrict source-code from being distributed in modified
form only if the license allows the distribution of "patch files" with
the source code for the purpose of modifying the program at build time.
The license must explicitly permit distribution of software built from
modified source code. The license may require derived works to carry a
different name or version number from the original software.
(rationale)
5. No Discrimination Against Persons or Groups.
The license must not discriminate against any person or group of persons.
(rationale)
6. No Discrimination Against Fields of Endeavor.
The license must not restrict anyone from making use of the program in
a specific field of endeavor. For example, it may not restrict the program
from being used in a business, or from being used for genetic research.
(rationale)
7. Distribution of License.
The rights attached to the program must apply to all to whom the program
is redistributed without the need for execution of an additional license
by those parties.
(rationale)
8. License Must Not Be Specific to a Product.
The rights attached to the program must not depend on the program's being
part of a particular software distribution. If the program is extracted
from that distribution and used or distributed within the terms of the
program's license, all parties to whom the program is redistributed should
have the same rights as those that are granted in conjunction with the
original software distribution.
(rationale)
9. License Must Not Contaminate Other Software.
The license must not place restrictions on other software that is distributed
along with the licensed software. For example, the license must not insist
that all other programs distributed on the same medium must be open-source
software.
(rationale)
We think the Open Source Definition captures what the great majority
of the software community originally meant, and still mean, by the
term "Open Source". However, the term has become widely used and
its meaning has lost some precision. The OSI
Certified mark is OSI's way of certifying that the license
under which the software is distributed conforms to the OSD; the
generic term "Open Source" cannot provide that assurance, but we
still encourage use of the term "Open Source" to mean conformance to
the OSD. For information about the OSI Certified
mark, and for a list of licenses that OSI has approved as conforming
to the OSD, see this page.
1.1 -- added LGPL to clause 10.
1.2 -- added public-domain to clause 10.
1.3 -- retitled clause 10 and split off the license list,
adding material on procedures.
1.4 -- Now explicit about source code requirement for PD software.
1.5 -- allow ``reasonable reproduction cost'' to meet GPL terms.
1.6 -- Edited section 10; this material has moved.
1.7 -- Section 10 replaced with new "Conformance" section.
Conformance
(This section is not part of the Open Source Definition.)Change history:
1.0 -- identical to DFSG, except for addition of MPL and QPL to clause 10.