Subject: Re: MS-RL equivalents?
From: Matthew Flaschen <>
Date: Wed, 21 Nov 2007 16:59:50 -0500

Tzeng, Nigel H. wrote:
> Is there an approved license like MS-Reciprocal License without the
> patent grant?  I have already rejected LGPL and MS-RL would be fine
> except I don't want to have to prove that my software isn't providing
> access to some patent created by some other inventor here.

GPLv2 doesn't have an explicit patent grant.  However, there's no
reciprocal license that explicitly doesn't have a patent grant.

> I simply want to convey the copyright of the software my team has developed
> with the knowledge that my team doesn't itself have any patents.

This is a very common concern, mentioned by MIT as well as other
academics. Thus far, OSI has not approved any reciprocal license that
meets your criteria.  There are several permissive licenses without
patent licenses.  Probably the best for your purposes is ECL v 2.0,
which specifically addresses this.  However, this was approved for a
tight group that promised to move to Apache.

> If not, I can recommend MS-RL with the proviso that each open source
> release much first verify that they aren't stepping on someone else's
> toes.

This is the real solution.  If your patent portfolio is so large and
unruly that this is impossible, you need to think seriously about
whether your patent policy needs to change.  After all, even large
companies like Sun have been willing to use licenses with patent grants.

MS-RL is similar to the more traditional Mozilla Public License.

Matt Flaschen