For approval: MXM Public license

John Cowan cowan at
Wed Apr 8 16:18:38 UTC 2009

Matthew Flaschen scripsit:

> On the other hand, BSD has "Redistribution and use in source and binary
> forms, with or without modification, are permitted".  This is a solid
> implicit patent license, and there is no attempt to disclaim it.

I'm very skeptical of this talk of implicit patent licenses.  For years
we assumed that the MIT license had an IPL because of the word "use",
and along comes MIT and disclaims that absolutely.

I don't think you can produce any language in the OSD that requires a
patent license as a condition of being open source.  OSD #3, per contra,
clearly requires a copyright license through the term "modifications
and derived works".

> Thus, I think this license is non-approvable in its own right, and very
> similar to unsuccessful past licenses such as Broad Institute Public License

The BIPL tried to *retroactively* exclude patent rights that the
license had granted, on the grounds that MIT couldn't keep track of what
conflicting exclusive rights it might have already granted.

> Open Source licensees should not fear being sued for simply exercising
> the rights laid out in the OSD.  The OSD says nothing about being
> limited to copyright.  "You can challenge the patent in court" is
> obvious and not a consolation.  You know full well that route is
> completely infeasible for most licensees.

In a world of submarine patents, *all* programmers must be prudent
about the risk of exercising the rights laid out in the OSD or anywhere
else.  It is hardly possible to write code at all without stepping on
some wrongly-decided patent.

A witness cannot give evidence of his           John Cowan
age unless he can remember being born.          cowan at
  --Judge Blagden                     

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