OSI is generally used as a registry for which licenses are real open source licenses. The 3D Slicer license currently isn’t listed with OSI. The License Review Process | Open Source Initiative provides an easy way to register new licenses and get them into the registry.
Thanks for raising this. You are right, it’s probably worth going through that process, since people do sometimes ask why the Slicer license is not in the registry. When this has come up before the feeling was that the OSI discouraged people from using non-standard licenses so we thought it would be rejected and that applying was not worth the effort. However the page you linked looks pretty reasonable and maybe they will now appreciate the reasons Slicer’s license includes a few protections that aren’t present in some simpler licenses while still being a very permissive open license.
@pieper would you try to submit the Slicer License for approval? It seems that the review is free and you just need to send the license to a mailing list. I guess the Slicer License would be “Legacy Approval” submission type with “Non-reusable licenses” proliferation category.
Okay, makes sense. Let me loop in Ron since he and I worked with the BWH lawyers to draft the license in the first place. I agree it belongs in the “non-reusable” category since it is written with BWH hard-coded in the language and it’s not possible for someone to just drop it into their own project even if they like the provisions.