The Reciprocal Public License (RPL) is a

copyleft Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...

software license A software license is a legal instrument (usually by way of contract law, with or without printed material) governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both sour ...

released in 2001. Version 1.5 of the license was published on July 15, 2007, and was approved by the

Open Source Initiative The Open Source Initiative (OSI) is the steward of the Open Source Definition, the set of rules that define open source software. It is a California public-benefit nonprofit corporation, with 501(c)(3) tax-exempt status. The organization w ...

as an

open-source license An open-source license is a type of license for computer software and other products that allows the source code, blueprint or design to be used, modified and/or shared under defined terms and conditions. This allows end users and commercial compan ...

Description

The RPL was authored in 2001 by Scott Shattuck, a software architect for Technical Pursuit Inc. for use with that company's TIBET product line. The RPL was inspired by the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end user In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ulti ...

(GPL) and authored to explicitly remove what the RPL's authors have referred to as the GPL's "privacy loophole". The GPL privacy loopholes allows recipients of GPL'd code to: #make changes to source code which are never released to the open source community (by virtue of not deploying "to a third party"), and #derive financial or other business benefit from that action, violating what some might consider a simple concept of "fairness". Because of its "

viral Viral means "relating to viruses" (small infectious agents). Viral may also refer to: Viral behavior, or virality Memetic behavior likened that of a virus, for example: * Viral marketing, the use of existing social networks to spread a marke ...

" nature, the RPL is often found in dual-licensing models in which it is paired with more traditional closed-source licenses. This strategy allows software companies who use this model to present customers with a "pay with cash or pay with code" option, ensuring either the growth of the software directly through code contributions or indirectly through cash which can be used to fund further development.

Reception

The RPL was written to conform to the requirements of the

to ensure that it met the goals for an Open Source license and is an approved

. However, because of its requirements for reciprocation without exceptions, it is considered to be non-free by the

Free Software Foundation The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985, to support the free software movement, with the organization's preference for software being distributed under copyleft ("s ...

. The license is used by Active Agenda, a risk-management web application, an
NServiceBus
an asynchronous messaging library for the .NET/ Mono platform. The RPL and GPL are used by OPC Foundation under the dual-licence scheme, where the former is used for members and the latter for non-members.OPC Foundation Github page.
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References

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External links

The Reciprocal Public License 1.5
hosted by the

The Reciprocal Public License 1.3
hosted by Technical Pursuit Inc. (archived link)
The Reciprocal Public License 1.1
hosted by the Open Source Initiative

hosted by Technical Pursuit Inc. (archived link) Free and open-source software licenses Copyleft software licenses