NPO Developers License

[Don Cameron]

Hoping this question is appropriate for this forum.

I am seeking a license suitable for a group of Non-Profits wishing to
develop and distribute software. The license should allow access to, and
modification of the source and prohibit reselling of original or modified
derivatives. This is to comply with NPO constitutional requirements that:
"donated products or merchandise must not be resold for profit". For the
purpose of distribution, all software developed would be deemed "a donated
product".

Is there such a license approved by OSI? I am unsure if a license that
prevents reselling  qualifies as Open Source - my reading of the OSI web
suggests that only licenses empowering for-profit redistribution
(commercial) are approved. 

If the license we need is not available or cannot be written and approved as
Open Source, maybe we need an envelope distribution license preventing
reselling that sits above and supplants any developmental license conditions
- any advice on ways to achieve this objective are appreciated.

Don