Report of License Proliferation Committee and draft FAQ

What Does License Proliferation mean?

One thing that became clear as we talked among ourselves and listened to the open source community was that different people meant different things when they used the term "license proliferation." Comments broke down into three main groups:

1. too many different licenses makes it difficult for licensors to choose
   Some people use "license proliferation" to mean that there are just too many licenses and that someone needs to take steps to reduce the number. While this would be great, the OSI cannot make anyone use or not use a particular license. All we can do is educate and urge people to use a smaller subset of licenses. This comment generally came from individuals and small companies.
2. some licenses do not play well together
   Some people use "license proliferation" to refer to the fact that some open source licenses do not inter-operate well with other open source licenses. While we can urge people not to mix non-mixable licenses, we cannot keep people from doing so. This comment generally came from larger companies.
3. too many licenses makes it difficult to understand what you are agreeing to in a multi-license distribution
   This is related to the previous comment, but is somewhat different since it doesn't complain about how the licenses interact, just that there are too many different individual licenses covering certain distributions and that it takes a lot of time to read and understand them all. This comment usually came from larger companies.

What the OSI Can Do About License Proliferation

The first thing we can do is to make sure that licenses calling themselves "open source" truly meet the Open Source Definition. In 2005, the OSI has suggested three guidelines that they would apply to proposed licenses to determine whether they should be OSI-approved.

1. The license must not be duplicative
2. The license must be clearly written, simple, and understandable
3. The license must be reusable

We propose addressing the license picking issue by making available a license wizard, as discussed below.

We propose an on-going project to group existing open source licenses. The goal of such categorization is to help the community determine which licenses are useful in which circumstances.

The Wizard Project

Volunteers from USC law school and San Francisco State engineering department are currently working on a web-based wizard to allow people to see which open source licenses meet criteria that they find important. These volunteers are Prof. Jennifer Urban and Prof. Sameer Verma, along with their research assistants. For example, if a user indicates that having a copyleft license with explicit patent grants is important, the wizard will look through the OSI-approved licenses and output a list of licenses that meet (or almost meet) those criteria.

The wizard assists new licensors in choosing which licenses meet their goals. The wizard also lets licensors find licenses that almost meet their goals. We hope that being able to generate a list of existing licenses that meet defined goals will lessen the need for people to create their own new licenses.

The Groups

Originally, the LP Committee started to divide the OSI approved licenses into "recommended," "non-recommended" and "other" tiers. The committee concluded, however, that any such normative characterization would properly be a matter for policy matter for the OSI Board to decide. Thus, we switched from the "recommended"/"non-recommended" terminology to a more descriptive terminology including the following categories:

• Licenses that are popular and widely used or with strong communities
• Special purpose licenses
• Licenses that are redundant with more popular licenses
• Non-reusable licenses
• Other/Miscellaneous licenses

We thought that these more descriptive categories would help people initially picking a license to use one of the more popular licenses, thereby helping to reduce the numbers of different licenses commonly used.

While it might at first sight not seem appropriate for the popularity of a license to be significant in categorizing it, popular and long-established licenses have an important thing going for them: the existence of an established interpretive tradition and a well-developed set of expectations about correct behavior with respect to them. This is significant in reducing confusion and (especially in common-law countries) is even likely to condition judicial interpretation of the licenses.

Here are the groups:

Licenses that are popular and widely used or with strong communities (9)

• Apache License, 2.0
• New BSD license
• GNU General Public License (GPL version 2)
• GNU Library or "Lesser" General Public License (LGPL version 2)
• MIT license
• Mozilla Public License 1.1 (MPL)
• Common Development and Distribution License
• Common Public License
• Eclipse Public License

Special purpose licenses (3)

• Educational Community License (special purpose: only suitable for educational establishments)
• NASA (special purpose: for use by an agency of the United States federal government, which has special concerns regarding some issues such as copyright protection, copyright notices, disclaimer of warranty and indemnification, and choice of law)
• Open Group Test Suite (special purpose: only suitable for tests or test suites)

Licenses that are redundant with more popular licenses (9)

• Academic Free License (redundant with Apache 2.0)
• Attribution Assurance Licenses (redundant with BSD)
• CUA Office Public License (redundant with MPL 1.1)
• Eiffel Forum License V2.0 (redundant with BSD)
• Fair License (redundant with BSD)
• Historical Permission Notice and Disclaimer (redundant with BSD)
• Lucent Public License Version 1.02 (redundant with CPL)
• University of Illinois/NCSA Open Source License (redundant with BSD)
• X.Net License (redundant with MIT)

Non-reusable licenses (24)

• Apple Public Source License
• Computer Associates Trusted Open Source License 1.1
• EU DataGrid Software License
• Entessa Public License
• Frameworx License
• IBM Public License
• Motosoto License
• Naumen Public License
• Nethack General Public License
• Nokia Open Source License
• OCLC Research Public License 2.0
• PHP License
• Python license (CNRI Python License)
• Python Software Foundation License
• RealNetworks Public Source License V1.0
• Reciprocal Public License
• Ricoh Source Code Public License
• Sleepycat License
• Sun Public License
• Sybase Open Watcom Public License 1.0
• Vovida Software License v. 1.0
• W3C License
• wxWindows Library License
• Zope Public License

Other/Miscellaneous licenses (5)

• Adaptive Public License
• Artistic License
• Open Software License
• Q Public License
• zlib/libpng license

Superseded licenses (4)

• Apache Software License v1.1
• Eiffel 1.0
• Lucent 1.0
• MPL 1.0

Licenses that have been voluntarily retired (4)

• Intel Open Source License
• Jabber Open Source License
• MITRE Collaborative Virtual Workspace License
• Sun Industry Standards Source License (SISSL)

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Here are our criteria for placing licenses in the various groups:

Licenses that are popular and widely used or with strong communities

We used statistics obtained from public sources to determine which licenses are widely used. We believed that there were a few licenses that, while not the most popular, were widely used within their communities and that these also belonged in this group.

Special purpose licenses

Certain licensors, such as schools and the US government, have specialized concerns, such as specialized rules for government copyrights. Licenses that were identified as meeting a special need were placed in this group.

Licenses that are redundant with more popular licenses

Several licenses in this group are excellent licenses and have their own followings. The committee struggled with this group, but ultimately decided that if we were to attack the license proliferation problem, we had to prune licenses. Thus, licenses that were perceived as completely or partially redundant with existing licenses were placed in this group.

Non-reusable licenses

Licenses in this group are specific to their authors and cannot be reused by others. Many, but not all, of these licenses fall into the category of vanity licenses.

Superseded licenses

Licenses in this category have been superseded by newer versions.

Licenses that have been voluntarily retired

Self-defining category. No one should use these licenses going forward, although we assume that licensors may or may not choose to continue to use them.

Other/Miscellaneous licenses

These licenses do not fall neatly into any category.