Licence/zh-cn

主要开发人员的声明
我知道关于"正确"的开源许可证的讨论占据了互联网带宽的很大一部分, 所以这里的原因是, 我认为, FreeCAD 应该有这一个.

我选择 LGPL 作为这个项目的许可证并且我知道关于 LGPL 的利与弊和将会给你一些关于该决定的原因.

FreeCAD 是一个库和一个应用程序的混合物, 所以 GPL 显得有点过于强大. 它将阻止为 FreeCAD 编写商业模块, 因为它会阻止与 FreeCAD 基础库的链接. 你可能会问为什么是所有的商业模块？因此, Linux 是一个很好的例子. 如果 GNU C 库是 GPL, 从而防止与非 GPL 应用程序的链接, Linux 会如此成功吗？虽然我喜欢 Linux 的自由, 我也希望能够使用非常好的 NVIDIA 3D 图形驱动程序. 我理解并接受 NVIDIA 不希望放弃驱动程序代码的原因. 我们都为公司工作, 需要至少为食物付款. 所以对我来说, 开放源码和封闭式源码软件的共存并不是一件坏事, 当它遵循 LGPL 的规则时. 我想看到有人写一个 FreeCAD 的导入/导出处理器, 并免费分发或需要支持一些钱. 我不喜欢强迫他放弃他想要的. 这对他和 FreeCAD 都不好.

Nevertheless this decision is made only for the core system of FreeCAD. Every writer of an application module may make his own decision.

Licences used in FreeCAD
FreeCAD uses two different licenses, one for the application itself, and one for the documentation:


 * Lesser General Public Licence, version 2 or superior (LGPL2+): For the core libs as stated in the .h and .cpp files in src/App src/Gui src/Base and all modules in src/Mod and for the executable as stated in the .h and .cpp files in src/main. The icons and other graphic parts are also LGPL.
 * Open Publication Licence: For the documentation on http://www.freecadweb.org when not marked differently by the author

See FreeCAD's debian copyright file for more details about the licenses used by the different components found in FreeCAD

Private users
Private users can use FreeCAD free of charge and can do basically whatever they want to do with it: use it, copy it, modify it, redistribute it. They are always master of their data, they are not forced to update FreeCAD, change their usage of FreeCAD. Using FreeCAD doesn't bind them to any kind of contract or obligation.

Professional users
Can use FreeCAD freely, for any kind of private or professional work. They can customize the application as they wish. They can write open or closed source extensions to FreeCAD. They are always master of their data, they are not forced to update FreeCAD, change their usage of FreeCAD. Using FreeCAD doesn't bind them to any kind of contract or obligation.

Open Source developers
Can use FreeCAD as the groundwork for own extension modules for special purposes. They can choose either the GPL or the LGPL to allow the use of their work in proprietary software or not.

Commercial developers
Commercial developers can use FreeCAD as the groundwork for their own extension modules for special purposes and are not forced to make their modules open source. They can use all modules which use the LGPL. They are allowed to distribute FreeCAD along with their proprietary software. They will get the support of the author(s) as long as it is not a one way street.

OpenCasCade License side effects (for FreeCAD version 0.13 and older)
The following is no more applicable since version 0.14, since both FreeCAD and OpenCasCade are now fully LGPL.

Up to Version 0.13 FreeCAD is delivered as GPL2+, although the source itself is under LGPL2+. Thats because of linkage of Coin3D (GPL2) and PyQt(GPL). Starting with 0.14 we will be completely GPL free. PyQt will be replaced by PySide, and Coin3D was re-licensed under BSD. One problem, we still have to face, license-wise, the OCTPL (Open CASCADE Technology Public License). Its a License mostly LGPL similar, with certain changes. On of the originators, Roman Lygin, elaborated on the License on his Blog. The home-brew OCTPL license leads to all kind of side effects for FreeCAD, which where widely discussed on different forums and mailing lists, e.g. on OpenCasCade forum itself. I will link here some articles for the biggest problems.

GPL2/GPL3/OCTLP incompatibility
We first discovered the problem by a discussion on the FSF high priority project discussion list. It was about a library we look at, which was licensed with GPL3. Since we linked back then with Coin3D, with GPL2 only, we was not able to adopt that lib. Also the OCTPL is considered GPL incompatible. This Libre Graphics World article "LibreDWG drama: the end or the new beginning?" shows up the drama of LibreDWG project not acceptably in FreeCAD or LibreCAD.

Debian
The incompatibility of the OCTPL was discussed on the debian legal list and lead to a bug report on the FreeCAD package which prevent (ignor-tag) the transition from debian-testing to the main distribution. But its also mentioned thats a FreeCAD, which is free of GPL code and libs, would be acceptably. With a re-licensed Coin3D V4 and a substituted PyQt we will hopefully reach GPL free with the 0.14 release.

Fedora/RedHat non-free
In the Fedora project OpenCasCade is listed "non-free". This means basically it won't make it into Fedora or RedHat. This means also FreeCAD won't make it into Fedora/RedHat until OCC is changing its license. Here the links to the license evaluation: The main problem they have AFIK is that the OCC license demand non discriminatory support fees if you want to do paid support. It has nothing to do with "free" or OpenSource, its all about RedHat's business model!
 * Discussion on the Fedora-legal-list
 * License review entry in the RedHat bug tracker