I'm interested in the Copyfree Open Innovation License as a simpler alternative to Apache 2.0 (it is a permissive license with an explicit patent grant).  But because it's not so popular, not much information is available about it.In particular, where does it fit into this graph? Image credit: David A. WheelerIs it GPL-compatible?  With which versions?  And where does it fit in with the permissive licenses?
Copyfree Open Innovation License compatibility
license compatibility
The Copyfree Open Innovation License License (CFOIL) is significantly shorter than the Apache 2.0 license. CFOIL grants:the right reproduce, modify, distribute, publish, sell, sublicense, use and/or otherwise deal in the licensed material without restriction; anda perpetual, worldwide, non-exclusive, royalty-free, irrevocable patent license to reproduce, modify, distribute, publish, sell, use, and/or otherwise deal in the licensed material without restriction; for any and all patents held by the licensor and any contributor that may be infringed by the work;provided that:the user retains applicable copyright or other legal privilege notices, these conditions, and the following license terms and disclaimer. Unlike Apache 2.0, CFOIL lacks the additional supporting elements for license enforcement that are present in Apache License 2.0. Specifically, it lacks language throughout the license that indicates that the license grants has the terms and conditions of the license is a precondition for the license grant.Apache 2.0, by constrast, is quite explicit about this:Subject to the terms and conditions of this License, each Contributor hereby grants ...Unlike Apache 2.0, CFOIL fails to make explicit that the specific intent of the drafters is to provide the license grant to only to those individuals or entities that abide by the terms and conditions contained in the license. Such an additional provision in the Apache 2.0 License strengthen the conclusion that the conditions in the license is, legally speaking a precondition rather than a covenant.  It also lacks the Apache 2.0 patent termination clause:If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed.which makes its embedded patent-license weaker than the one in Apache 2.0.In fact, its patent terms seems incompatible with any copyleft license. In practice, these flaws in this license will limit your options (compared to Apache 2.0) if you want to seek legal remedy for license violations.  If all you want to have a really permissive license with a (sort of) patent license embedded, and do you will not even think about pursuing license violations, and do not fear patent suits filed from contributors will pose a problem, and you don't care about license compatibility, then it may be OK.But if your alternatives are this license and Apache 2.0, you should be aware of the differences.  Apache 2.0 is IMHO superior.As far as license compatibility goes, I don't think it is compatible with any version of the GPL or any other copyleft license.  It looks like a permissive license but its messed up patent license clause rules out GPL comptability and compatibility with Apache 2.0So I can understand why this one is not much used, as it:creates legal uncertanity (contra proferentem)creates license proliferation for no good reason;So to conclude: I don't think it fits anywhere on the license map reproduced in the question.