[laken]

> Basically, if I have to license my project on GPL because of CGAL, I would like the scripts wrote by user could license on whatever user like. But I am not sure if is possible.

It'd have to be a "compatible" license to be allowed. Here are the compatible licenses: https://www.gnu.org/licenses/license-list.en.html#GPLCompati...

[huxingyi]

Thanks, so that means the user have to open source their script also.

[laken]

Kinda. If it's strictly for personal use and not shared, there's no obligation. If the user is distributing the script in any way, they would be obligated to "share" the changes to the world by having it be free software as well, yes.