As QT is GUI Framework for Slicer, and QT has two types license, LGPL and GPL.
LGPL includes: Core, Widgets, QML and so on.
GPL includes Qt Chats and so on.
As I develop a product, built as an extension, running on Slicer platform. I change some logo, or view controller font in C++, others codes are written by Python.
So I want to know, the product of extension can be used in commerical without open source? @lassoan
We don’t use any GPL-licensed components for building 3D Slicer. You are free to use it for commercial purposes, for free, without asking permission from anyone.
Note also that if you choose to use GPL licensed portions of Qt or use Qt in a way that is inconsistent with the terms of the LGPL you may need a commercial license to Qt. For a commercial product this is generally not a problem so you should do it if required by the terms of the licenses.
The following page is useful to find out which licenses are used by each Qt components and dependencies. See Licenses Used in Qt | Qt 5.15