[License-review] For Approval: Convertible Free Software License, Version 1.3 (C-FSL v1.3)

Elmar Stellnberger estellnb at elstel.org
Tue Jan 8 15:56:52 UTC 2019

Full Name: Convertible Free Software License Version 1.3
Short Identifier: C-FSL v1.3
URL1: https://www.elstel.org/license/C-FSL-v1.3.pdf
URL2: https://www.elstel.org/license/C-FSL-v1.3.txt

Rationale and Distinguish:
While the BSD license allows the whole world to re-license and while 
re-licensing is virtually impossible with GPL since every contributor 
would need to consent the C-FSL license goes a practical intermediate 
way restricting the right to re-license to a group called the original 
authors. That way open source developers are not excluded from making 
business with others who want to base a proprietary product on the given 
piece of open source software.

Proliferation Category & Legal Review:
The license has now been fully reworked by a lawyer. Besides this 
Version 1.3 features easier and more user friendly forking.

list of software which uses C-FSL v1.1.:
qcoan: https://www.elstel.org/coan
xchroot, confinedrv, bundsteg, debcheckroot, dbschemacmd: also found at 

P.S.: Please excuse that I have forgotten to attach the license in my 
last mail; apart from this this mail is just the same.
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v1.3, 21.12.2018

Copyright © 2018 Elmar Stellnberger. <https://www.elstel.org/license>
Everyone is permitted to copy and distribute verbatim copies of this licence document, but changing it is not allowed.

By continuing to use the Works or Derivative Works under this Licence, You are agreeing to this version and any future versions of this Licence. 



“Licence” shall mean the Convertible Free Software Licence (C-FSL).

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To “modify” a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. 

"Derivative Work(s)" shall mean any work, whether in Source or Object form, that is based on, or derived from, the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. 

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5.1 You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions:

a) You must release any Work or Derivative Works under this Licence to the public at no cost and without any undue hindrance on obtaining the Work. For the avoidance of doubt, requesting that users register before they are able to use the Work or other similar action, shall be considered an undue hinderance and shall therefore not be permitted as per the provisions of this Clause. 
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6.1 The Original Authors of the Work shall be listed at the beginning of the changelog file or the header of file changes of Your Derivate Work. 

6.2 You may re-licence your Derivative Work separately under any Licence you desire, without a Marker and only with the prior written consent of the Original Authors. In such event, new Contributors may be added to the Original Authors’ group.


7.1 You may create a Fork of an Original Branch under this Licence with a different name on the condition that you provide a clear indication that the Fork is based on the Original Branch.

7.2 If Your Fork uses a graphical user interface (“GUI”), this Licence must be referenced in its entirety within the GUI, or, where your programme does not have a GUI, the Licence must be cited through a plain text copy alongside the distributed Work. The Original Branch must be referenced and linked via the GUI.

7.3 If Your Fork is released with a comprehensive manual or help page, the Original Branch must be referenced and linked. 

7.4 If Your Fork is released with a comprehensive manual or help page, the Licence must be referenced and linked. 

7.5 If the Fork comprises 65% or more code that is different to that of the Original Branch, then new Original Authors may be appointed. 

7.6	Notwithstanding the provisions in 7.4 above, new original authors may be appointed with the written consent of the Original Authors. 

7.7 If a Work under this Licence comprises several Libraries which can each be compiled or used independently, the Libraries may be considered independent Works. In such event, the Library name shall be included in the file header. Clause 7.4 above shall apply to each Library independently. For the avoidance of doubt, Libraries licensed under Version 1.1 of the C-FSL do not need to be named as main Works in the file header to qualify as an independent Work.


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