Eclipse Public License (hereinafter EPL) is a type of Open Source Software license and is approved by the Open Source Initiative. The EPL replaces the Common Public License (hereinafter CPL). IBM was the Agreement Steward for the Common Public License. The EPL changes the Agreement Stewart, IBM to the Eclipse Foundation. The license is used by the Eclipse Foundation for its software.
The EPL has weaker copyleft provisions than other OSS licenses, though. Under EPL, the licensee/ recipient is entitled to use, modify, copy and distribute the work and modified versions, in some cases being obligated to release their own changes. The Eclipse Foundation supports business and commercial friendly free software licenses.
As readers may recall, copyleft licenses grant the freedom to reproduce, adapt, modify or distribute the work as long as any resulting copies, modifications or adaptations are also distributed under the same terms. EPL is a copyleft license; however it is non-viral in nature. In other words, it applies only to the source of what was licensed. This does not apply to any modifications made to a project governed by EPL. The terms of General Public License (GPL) also embody the principle of copyleft. The GPL makes it necessary that if a distributed work contains or is derived from a GPL licensed program, such work be licensed as a whole. It also obligates that the distributor should not impose any further restrictions on the recipients’ exercise of the rights granted.
In contrast to the GPL, the EPL requires that anyone distributing the work is obligated to grant every recipient a license to any patents that they might hold that cover the modifications they have made. It is not legal to distribute a work that encompasses works that are separately licensed under the GPL and EPL. The incompatibilities between the EPL and GPL are highlighted as under:
- Patent Retaliation Clause: The EPL has a clause incorporating patent retaliation. The objective of a patent retaliation clause is to prevent a licensee/ recipient/ user of the free software license from suing the licensor for patent infringement. This goal is effectuated by adding a right to terminate the license upon initiation of such lawsuit or court proceeding by the licensee.
- Derivative Works: Another factor that adds to the incompatibility is EPL’s provisions covering derivative works. By virtue of Article 1(b) of the EPL, additions to the original work may be licensed independently, including under a commercial license, provided such additions are separate modules of software and do not constitute a derivative work. If such additions/ changes fall within the ambit of derivative work, such work must be licensed under the same terms and conditions of the EPL, which includes the requirement to make source code available. The user in an EPL has the right to compile a program licensed under the EPL without modifying it and commercially license the result in such a way that it does not conflict with the terms of the EPL.
The EPL is an integral part of several software projects such as Symbian, Graphviz, Clojure, Mondrian OLAP server, Open Daylight Project and UWIN. The source code associated with the aforementioned are released under the EPL. The initial and latest version of the EPL is Version 1.0.
The Intellectual Property Policy of the Eclipse Foundation specifies the general principles under which the Eclipse Foundation shall accept contributions, license contributions, license materials owned by the Eclipse Foundation, and manage other intellectual property matters. A contributor/ licensor in an EPL must identify itself as the originator of its contribution.
By Aruna Mukundd