Executive summary: I did not yet sign the CLA and see no reason to sign it in a near future. I explain why in this post, and propose an arrangement.
Disclaimer: this is my own opinion about CLA, it is not a position statement reflecting OCE members' view.
First of all, a CLA is not mandatory in many cases, since only "significant works" are copyrightable. For instance, trivial patches like the one at http://www.opencascade.org/org/forum/thread_22364/ does not need a copyright assignment. All patches I submitted up to now on OCC forum can IMHO not be considered as copyrightable, they fix build failures or help porting to unsupported platforms, but there is no new feature.
In OCE, CMake files are the only new feature which may be considered as copyrightable (or not).
Next, I hack on OCC during my free time, I am not paid for that and do not try to make money with my contributions. Thus I am not interested in signing a contract without a compensation.
I know that many free software projects enforce signing a CLA before contributing. I have the same opinion about these projects, and never signed a CLA before, even from the FSF. (To be fully honest, I signed http://translationproject.org/html/whydisclaim.html but it is about translations only, not code)
Of course I can change my mind later, but at the moment I am not interested in signing a CLA.
On the other hand, many free software hackers claimed in the past that they dislike the OCCT Public License. For instance, it took many hours to convince the Debian project that this license is a free software license. Fedora had a different position, they rejected it and OCCT libraries are not distributed as official packages.
Another problem is that OCCTPL is incompatible with the GNU GPL. See for instance consequences at http://bugs.debian.org/617613
This is very frustrating, we free software hackers would very much prefer spending our time on writing code instead of sending mails to discuss legal stuff we are not interested in.
So, here is a deal. If you relicense OCCT to a well known GPL-compatible license (preferably LGPL of course, but any license listed at http://www.gnu.org/licenses/license-list.en.html#GPLCompatibleLicenses should work), this will save us from spending hours on boring stuff, and I will then sign the CLA.
This is a proposition and not a blackmail, I may be convinced to sign the CLA without changing the OCCT license, but I believe that this is a good deal for all parties.
Thanks for reading.