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FAQ page updated!

Forum supervisor's picture

Dear Community,

OPEN CASCADE Team is happy to announce that a new Frequently Asked Questions section of is available. The new FAQ is based on real questions answered on our forum . If you feel that any important questions still require explanation, please, send your suggestions to our contact form.

Read the new FAQ:

Sincerely yours,
Forum Supervisor

Arthur Magill's picture

Thank you for updating the FAQ. It is now makes OCCTs position on licensing and bugtracking very clear. It is sad that OCCT is determined to stick with the GPL-like license (which is classified as non-free by Debian legal), rather than a widely recognised open source license, as this prevents major Linux distributions from packaging OCC. But at least the position is now clearly stated.

I find it rather amusing that the same document explains how no public bugtracker or repository will be made available, and notes that no significant contribution has been made by the open source community. Maybe there is a link here?

But in the end we can continue to use OCC in open source projects, and for that I have to say thank-you.

Timo's picture

The link to on the FAQ page does not work.

Kind regards,

Forum supervisor's picture

Thank you, Timo.
The link was corrected.
Best regards,
Forum supervisor

Bryan Bishop's picture

The second question in the FAQ is unclear. It presently says:

"2) Can I distribute my software product using Open CASCADE Technology under GPL license? No, you are not allowed to license your derived work under GPL. You should use OCCT license instead."

I think that the question is asking about software using OCC. However, the answer is about derivatives of OCC. After watching the OCC forums for a while now, I don't recall anyone asking about licensing a derivative of the OCCT platform itself, so I don't see what good it could do other than confuse the issues. So, is pythonOCC a derivative? What about HeeksCAD or FreeCAD? So far no project has actually made a derivative of OCCT in the sense of rewriting it or merging in their own patchsets, so that FAQ item might need some revision.

"1) Is Open CASCADE Technology license GPL-compatible? No, it is not. OPEN CASCADE Company uses its own custom license. However, it follows LGPL license in many aspects."

Well, sort of. I suggest reading:

"To acknowledge that your software uses OCCT, you need to include the OCCT Public License into the distribution package and add the mention of OCCT into the information about your software (Read me, About box, etc.)"

Acknowledging that your software uses OCCT (such as by static/dynamic linking) doesn't seem to be a requirement according to the license on:

I should just pony up the money and buy OCC S.A.S. entirely, and have these issues resolved. :-)

HTH & Cheers,

- Bryan
phone: +1-512-203-0507

Roman Lygin's picture

Good to have this initiative with FAQ started. Thanks the team for that !

Bryan makes a right point regarding #2. OCC license does *NOT* prevent you from choosing any license for your product that uses OCC - be it GPL, proprietary or any other one. What OCC license *DOES* require is that any modifications in OCC must be available under OCC license (again, this does not prevent from making them available under any other license).

So I would suggest that OCC team rewords this #2 - either making it focused on modifications issue, or giving a correct answer. It is definitively misleading in its current form.

Again, my 2 cents. If LGPL were adopted for OCC, it would be much more clear for everyone and saved a lot of time in debates ;-)


Forum supervisor's picture

Thank you for your remarks, Roman. Item #2 was updated.

Forum supervisor's picture

Bryan, thank you for your comments. We've updated item #2.