The OSI has received several inquiries concerning its opinion on the licensing of React , which is essentially the 3-clause BSD license along with, in a separate file, an 'Additional Grant of Patent Rights' .
The Additional Grant of Patent Rights is a patent license grant that includes certain termination criteria. These termination criteria are not entirely unprecedented when you look at the history of patent license provisions in OSI-approved licenses, but they are certainly broader than the termination criteria [or the equivalent] in several familiar modern licenses (the Apache License 2.0, EPL, MPL 2.0, and GPLv3).
The 'Additional Grant' has attracted a fair amount of criticism (as did an earlier version which apparently resulted in some revisions by Facebook). There was a recent blog post by Robert Pierce of El Camino Legal  (which among other things argues that the React patent license is not open source). Luis Villa wrote an interesting response .
What do members of the license-discuss community think about the licensing of React? OSI Board Director Richard Fontana posed a few issues to the OSI's License Discuss forum (you can see the thread here):
- does the breadth of the React patent termination criteria raise OSD-conformance issues or otherwise indicate that React should not be considered open source?
- is it good practice, and does it affect the open source status of software, to supplement OSI-approved licenses with separate patent license grants or nonasserts? (This has been done by some other companies without significant controversy.)
- if the React patent license should be seen as not legitimate from an OSI/OSD perspective, what about the substantial number of past-approved (if now mostly obsolete) licenses that incorporated patent license grants with comparably broad termination criteria?
- should Facebook be encouraged to seek OSI approval for the React license including the patent license grant?
Please note, at the time of this post and discussion, Facebook was a Corporate Sponsor of the Open Source Initiative. https://facebook.github.io/react/  https://github.com/facebook/react/blob/master/PATENTS  http://www.elcaminolegal.com/single-post/2016/10/04/Facebook-Reactjs-License  http://lu.is/blog/2016/10/31/reacts-license-necessary-and-open/