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.:: Document
Index ::.

*The
Open Source Definition
*The Halloween
Documents
*OSI Press
Releases
*OSI
Certification Mark
*OSI Approved
Licenses
*Peru Answers
MS F.U.D.
*OSI's
History in connection to OSI Site
History
*On
'shared source'
*Graphics and
Trademarks

.:: OSD change
log ::.

*1.0
identical to DFSG, except for addition of MPL and QPL to
clause 10.
*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.
*1.8
Section 1: replaced "may not" with "shall not".
*1.9
Section 9: removed rationale referring to the action of the
GPL as Contaminat[ion].
* Section 10 added.
* Site History

.:: Conformance
to the OSD ::.

(This section is not part of the Open Source
Definition.)

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 the OSD Certification
Mark page.

The Open Source Definition

Version 1.9

The indented, italicized sections below appear
as annotations to the Open Source Definition (OSD) and
are not a part of the OSD. A plain version of
the OSD without annotations can be found here.

A printable version of this annotated page is
available here.

Introduction

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 shall 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 shall not require
a royalty or other fee for such sale.

Rationale: By constraining the license to
require free redistribution, we eliminate the
temptation to throw away many long-term gains in order
to make a few short-term sales dollars. If we didn't
do this, there would be lots of pressure for
cooperators to defect.

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: We require access to
un-obfuscated source code because you can't evolve
programs without modifying them. Since our purpose is
to make evolution easy, we require that modification
be made easy.

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: The mere ability to read
source isn't enough to support independent peer review
and rapid evolutionary selection. For rapid evolution
to happen, people need to be able to experiment with
and redistribute
modifications.

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: Encouraging lots of
improvement is a good thing, but users have a right to
know who is responsible for the software they are
using. Authors and maintainers have reciprocal right
to know what they're being asked to support and
protect their reputations.

Accordingly, an open-source license must
guarantee that source be readily available, but
may require that it be distributed as pristine
base sources plus patches. In this way, "unofficial"
changes can be made available but readily
distinguished from the base
source.

5. No Discrimination Against Persons or
Groups

The license must not discriminate against any person
or group of persons.

Rationale: In order to get the maximum
benefit from the process, the maximum diversity of
persons and groups should be equally eligible to
contribute to open sources. Therefore we forbid any
open-source license from locking anybody out of the
process.

Some countries, including the United States,
have export restrictions for certain types of
software. An OSD-conformant license may warn licensees
of applicable restrictions and remind them that they
are obliged to obey the law; however, it may not
incorporate such restrictions
itself.

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: The major intention of this
clause is to prohibit license traps that prevent open
source from being used commercially. We want
commercial users to join our community, not feel
excluded from it.

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: This clause is intended to
forbid closing up software by indirect means such as
requiring a non-disclosure
agreement.

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: This clause forecloses yet
another class of license
traps.

9. License Must Not Restrict 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: Distributors of open-source
software have the right to make their own choices
about their own software.

Yes, the GPL is conformant with this
requirement. Software linked with GPLed libraries only
inherits the GPL if it forms a single work, not any
software with which they are merely
distributed.

*10. License Must Be Technology-Neutral

No provision of the license may be predicated on any
individual technology or style of interface.

Rationale: This provision is aimed
specifically at licenses which require an explicit
gesture of assent in order to establish a contract
between licensor and licensee. Provisions mandating
so-called "click-wrap" may conflict with important
methods of software distribution such as FTP download,
CD-ROM anthologies, and web mirroring; such provisions
may also hinder code re-use. Conformant licenses must
allow for the possibility that (a) redistribution of
the software will take place over non-Web channels
that do not support click-wrapping of the download,
and that (b) the covered code (or re-used portions of
covered code) may run in a non-GUI environment that
cannot support popup dialogues.

Origins: Bruce Perens
wrote the first draft of this document as "The Debian Free
Software Guidelines", and refined it using the comments of the
Debian developers in a month-long e-mail conference in June,
1997. He removed the Debian-specific references from the
document to create the "Open Source Definition."

Copyright © 2004 by the Open Source
Initiative
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