CPL Defensive Termination

JUnit relicensing EPL for Netbeans and OpenJDK


3. Specifically how does the EPL 1.0 differ from the CPL?

Section 7 of the CPL contained the following language:

“If Recipient institutes patent litigation against a Contributor with respect to a patent applicable to software (including a cross-claim or counterclaim in a lawsuit), then any patent licenses granted by that Contributor to such Recipient under this Agreement shall terminate as of the date such litigation is filed. In addition, if Recipient institutes patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Program itself (excluding combinations of the Program with other software or hardware) infringes such Recipient’s patent(s), then such Recipient’s rights granted under Section 2(b) shall terminate as of the date such litigation is filed.”

The first sentence was removed in the EPL 1.0. Many members and prospective members believed that the first sentence was overly broad and viewed it as an inhibitor to the continued growth of the Eclipse eco-system. The second sentence remains unchanged in the EPL 1.0.

The current Eclipse Foundation Intellectual Property Policy further clarifies 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.


Some companies do not want to in-license software under this kind of patent termination provision. Their concern is with the first half of section 7, which applies to infringement litigation “with respect to a patent applicable to software.” This is the scenario they don’t like: Suppose Company A licenses its software under the CPL to Company B. Company B then accuses Company A of infringing an entirely different software patent unrelated to the licensed software. Company B’s license to the software terminates.

Should Company B have accepted Company A’s software in the first place? Should it ever accept the risk of relying on open source software under the CPL if by doing so it may make the rest of its software patents unenforceable against Company A?

Some companies refuse to accept such license conditions. Open source projects need to decide whether such license conditions will frighten away too many prospective licensees. This may also present an opportunity for open source projects to use dual licensing, where they can offer a lower risk license alternative to such risk-averse companies—at a price. (See the discussion of dual licensing in Chapter 11.)

By the way, this situation can occur under the MPL as well. Under the defensive termination provisions in both the MPL and CPL, the licensor’s patent licenses terminate if the licensee sues the licensor for patent infringement. Under both MPL and CPL, a licensee may eventually have to choose between continuing the license and suing for patent infringement.

Is that really such an unreasonable bargain? In return for accepting valuable free software from Company A, Company B must accept that its software patents are effectively unenforceable against Company A. But the software is free! Why should it not come at a price? Why isn’t reciprocity of patent licenses a reasonable bargain?