From: Lucas Nussbaum <lucas@...>
Date: 2010-09-01T23:41:48+09:00
Subject: [ruby-core:31996] Re: Change Ruby's License to BSDL + Ruby's dual license

On 01/09/10 at 23:18 +0900, NARUSE, Yui wrote:
> Yes, your proposal: change to BSDL single license is good point.
> But it has some side effect:
> * lost non-standard name clause 2.c) and 3.c)

Those are additional restrictions. They are actually void, because the
modifier or the redistributor could just choice to place its work under
BSL.

> * lost "arrangements with the author" clause 2.d) and 3.d)

Same here: I could modify Ruby and place my modifications or my
redistribution under BSD without doing any of 2.a, 2.b, 2.c, 2.d.

> * lost 4.

This is already permitted by the BSD license anyway.

> If someone uses those clause, they can't update the code from Ruby.
> So such change needs more care.

So, to summarize, there are two cases:
- clauses where the Ruby license adds additional restrictions, compared
  to BSD (example: 2.* 3.*):
  Then it is possible to circumvent those restrictions by using BSD
  only.
- clauses where the BSD license adds additional restrictions, compared
  to Ruby's: 
  the only clause in that case is the fact that you must retain the
  copyright notices. That doesn't sound serious enough to warrant dual
  licensing. And if that's really a problem, you could actually remove
  that clause from the BSD license.

- Lucas