Since occ will discuss the relicensing of open CAS.CADE (as discussed in a previous thread), I think it would be a great idea to also take into account the following issues :

1) Discuss the opening of CAS.CADE products (emesh, guif etc...), under a license that will protect your interests and assets, but will also give a boost to open source applications, and demonstrate widely occ's added value products.An example would be a dual licensing scheme such as, GPL for the open source version (protect inclusion in non free software), and a fee based custom license for paying customers (probably the existing license).I am in no case a licensing expert, so i am not sure if such a thing can be even done.In any case it would be a very welcome addition to the open source world.

2) Open to the public, the binary advanced samples demo versions (this was the case many years ago from the .com site). It can provide a wider audience of some advanced occ features.


Daniel Brunier-Coulin's picture

Good point to be considered. On the other hand, relicensing OCC Products to a dual license GPL and commercial would probably require to open their development. I expect we are not ready for that.

Anyway, the first priority is to relicense OCCT, most probably to LGPL.


Bruno's picture

hi, i am new in this forum.Sorry for my poor english i'm french.why not use a "no copyleft" licence like BSD Licence?

james smith's picture

Two words: Corporate Suicide.

Arthur Magill's picture

Funny, it seemed to work well for VTK. You could maybe argue that they serve a different market (or maybe not), but the license has been very successful for them.

From their FAQ:

Can VTK be used as part of a project distributed under a GPL License?

Short Answer

Yes, it is fine to take VTK code and to include it in a project that is distributed under a GPL license.

Long Answer

Let's call project X the larger project that:

Will include source code from VTK (in part or as a whole)
Will be distributed under GPL license

Note in particular that:

The copyright notices in VTK files must be kept.
If VTK files are modified by the developers of project X, that fact must be clearly indicated.
Only the modifications of VTK files made by the developers of project X will be covered by a GPL license. The original VTK code remains covered by the VTK license.
The collection of copyrighted works (project X in this case), that includes VTK (in part or as a whole) and their software will be covered by a GPL license.


As the VTK license is a variation of the Modified BSD license, to which only the following term has been added:

Modified source versions must be plainly marked as such,
and must not be misrepresented as being the original software.

and that the Modified BSD license is itself compatible with the GPL (Modified BSD license)

Then the VTK license is also compatible with the GPL license. Since the terms of the GPL license do not preclude the additional term of the VTK license from being followed.

NOTE: The licenses are only one way compatible.

You can use VTK code inside a GPL licensed project.
You can not use GPL licensed code inside VTK.

That is the reason why there are no GPL third party libraries in VTK. Having GPL third party libraries in VTK would prevent closed source projects from being built against VTK.

james smith's picture

True, but you could consider, opening the advanced examples, or provide a few other more advanced code examples. The problem with many people I have talked to about OCC is that the documentation is weak, the learning curve steep, the examples are limited, and when people download it and try to use it for a while they are left with an undeserved bad overall impression. OCC in its present "presentation", gives the impression of a very harsh and esoteric API.
As far as the overall license is concerned, id do believe that LGPL would in fact be the closest to the existing OCC public license.

Daniel Brunier-Coulin's picture

For your information, the decision to relicense OCCT is postponed for several months.

It’s undoubtedly a postponement, not an abandonment and it does not change the aim of our project and our commitment to meet the needs of the community. Especially, our plan to publish the repository and the test framework remains unchanged, and we invite you to not wait for a relicensing and to join us now by signing the CLA.


Denis's picture

Thanks for the heads up; FWIW my position is unchanged.