9. Acceptance and Termination

OSL

AFL

If You distribute copies of the Original Work or a Derivative Work, You must make a reasonable effort under the circumstances to obtain the express assent of recipients to the terms of this License. Nothing else but this License (or another written agreement between Licensor and You) grants You permission to create Derivative Works based upon the Original Work or to exercise any of the rights granted in Section 1 herein, and any attempt to do so except under the terms of this License (or another written agreement between Licensor and You) is expressly prohibited by U.S. copyright law, the equivalent laws of other countries , and by international treaty. Therefore, by exercising any of the rights granted to You in Section 1 herein, You indicate Your acceptance of this License and all of its terms and conditions. This License shall terminate immediately and you may no longer exercise any of the rights granted to You by this License upon Your failure to honor the proviso in Section 1(c) herein.

If You distribute copies of the Original Work or a Derivative Work, You must make a reasonable effort under the circumstances to obtain the express assent of recipients to the terms of this License. Nothing else but this License (or another written agreement between Licensor and You) grants You permission to create Derivative Works based upon the Original Work or to exercise any of the rights granted in Section 1 herein, and any attempt to do so except under the terms of this License (or another written agreement between Licensor and You) is expressly prohibited by U.S. copyright law, the equivalent laws of other countries, and by international treaty. Therefore, by exercising any of the rights granted to You in Section 1 herein, You indicate Your acceptance of this License and all of its terms and conditions.

The OSL/AFL licenses are designed to be enforced as contracts, and the law requires that parties to a contract expressly assent to its terms. Most courts don't really care what form that assent takes, as long as it is manifested by some definite action. For software, this often means a shrink-wrap or click-wrap procedure by which the licensee indicates awareness of the license and accepts it, but the OSL/AFL mandate neither procedure.

The OSL/AFL requirs that downstream licenses for Copies and Derivative Works also be accepted as contracts. They mandate no particular method, but they require that downstream licensors exercise a "reasonable effort under the circumstances" to obtain assent. If those reasonable efforts are undertaken, the OSL/AFL will be enforceable as contracts.

But even ignoring contract law, the second and third sentences of section 9 make it clear that "nothing else but this license" allows anyone to use this software. This provision was taken from the GPL license, because it describes, in clear terms, the interdependence of copyright and contract law.

Here's how the argument goes: Anyone who copies, modifies, or distributes the licensor's software without a license is an infringer . The law punishing infringers is the U.S. copyright law, the equivalent laws of other countries, and international treaties . So anyone found using the software is either an infringer or a licensee. The OSL/AFL say that, by exercising the licensor's exclusive rights, either a user indicates acceptance of the license, or else the user is admitting that he or she is an infringer.

The final sentence of section 9 applies only to the OSL, because only the OSL contains a reciprocity provision. Once a contract is in effect it can be terminated . The OSL terminates if the licensee fails to honor the reciprocity condition in section 1(c). This puts teeth into the reciprocity bargain. A licensee cannot pick and choose which parts of this license to honor. Failure to distribute derivative works under the same OSL is a breach of contract and grounds for terminating the license immediately.

Comparison to Other Licenses

The BSD, MIT, Apache, and Artistic licenses say nothing about contract formation or termination.

The basic concept for section 9 of the OSL/AFL came from the GPL. It uses similar language to assert the primacy of copyright law. However, the GPL is not intended to be enforced under contract law, so the first sentence of OSL/AFL section 9 (express assent) and the last sentence of OSL section 9 (termination for failure to honor the reciprocity provision) don't have analogues in the GPL.

The MPL says nothing about contract formation but it does include two termination clauses. The first says that the MPL license terminates:

...If You fail to comply with terms herein and fail to cure such breach within 30 days of becoming aware of the breach. ( MPL section 8.1.)

That termination provision is broader and applies in more situations than the termination provision of the OSL, which automatically terminates only for failure to honor the reciprocity provision. Terminating the OSL for other forms of breach would probably require the licensor to file a lawsuit. (See the discussion of the attorneys ' fees provision in section 12, below.)

The second termination clause of the MPL will be discussed in section 10, termination for patent action.

The CPL also contains two termination provisions. One, relating to termination for patent action, will be discussed in section 10 below. The other is similar to the MPL:

All Recipient's rights under this Agreement shall terminate if it fails to comply with any of the material terms of conditions of this Agreement and does not cure such failure in a reasonable period of time after becoming aware of such noncompliance . ( CPL section 7.)

Again, this is broader and applies in more situations than the OSL's termination for failure to honor the reciprocity condition, but in either situation a licensor may have to go to court to terminate the license. This is discussed in more detail in Chapter 12, Open Source Litigation.