Open Source Definition

The Open Source Definition is used by the Open Source Initiative to determine whether or not a software license can be considered open source.

The definition was based on the Debian Free Software Guidelines, written and adapted primarily by Bruce Perens. They are by no means definitive even as applied to software. Clause 3 is the primary legal difference between free software and open source software as such, free software is stricter in interpreting 3. Clauses 5 and 6 are not a condition of any major open content license regimes, which commonly do restrict types of uses and users; for instance, Creative Commons has open content licenses that explicitly forbid commercial use.

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.

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.

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.

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.

5. No Discrimination Against Persons or Groups

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

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.

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.

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.

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.

10. License Must Be Technology-Neutral

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

Definitions

There are numerous groups who claim ownership of the term "Open Source", but the term has not been trademarked. The Open Source Initiative's definition is widely recognized as the standard or de facto definition.
The Open Source Initiative (OSI) was formed in February 1998 by Raymond and Perens. With about 20 years of evidence from case histories of closed and open development already provided by the Internet, the OSI continued to present the 'open source' case to commercial businesses. They sought to bring a higher profile to the practical benefits of freely available source code, and wanted to bring major software businesses and other high-tech industries into open source. Perens adapted Debian's Free Software Guidelines to make The Open Source Definition.

 

The Open Source Definition

The Open Source Definition is used by the Open Source Initiative to determine whether a software license can be considered open source. The definition was based on the Debian Free Software Guidelines, written and adapted primarily by Bruce Perens.Perens did not base his writing on the "four freedoms" of Free Software from the Free Software Foundation, which were only widely available later.

 

Perens' principles

Under Perens' definition, open source describes a broad general type of software license that makes source code available to the general public with relaxed or non-existent copyright restrictions. The principles, as stated, say absolutely nothing about trademark or patent use and require absolutely no cooperation to ensure that any common audit or release regime applies to any derived works. It is an explicit "feature" of open source that it may put no restrictions on the use or distribution by any organization or user. It forbids this, in principle, to guarantee continued access to derived works even by the major original contributors.

Reference 

http://en.wikipedia.org/wiki/Open-source_software#History
http://opensource.org/docs/osd