I have downloaded a currently inactive GPL project with a view to updating it and releasing the completed codebase as open source. I'm not really a fan of GPL though and would rather licence my project under BSD.

What are my options? Is it just a case of keeping any existing non-touched code under the GPL and any updated stuff can be BSD (messy)? The source will essentially be the same codebase i.e. there is no logical separation between the two and they certainly can't be split into anything resembling different libraries.

Are my only realistic options to either GPL the whole thing or seek the original author's permission to release everthing under BSD?

  • 1
    Yes, those are your only realistic options. Be prepared for a compromise; if it is a library, ask him if you can get an LGPL license for it. Oct 17, 2012 at 22:00

2 Answers 2


Effectively, yes. If you create a derived work from the original project, you're bound by the existing license. You can't relicense it without releases from any (or every) copyright holder.

You might ask the original author(s) if they would consider dual-licensing, e.g. like the Perl Artistic License, but putting a BSD-style license (which would allow other people to take their work, make changes to it, and remove it from the public good) on a program that's currently under GPL would probably be a surprising turn of events.

In the GPL v3, the relevant clause begins,

You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions: c) You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy.

It does (somewhat) depend upon the license under which you received the program; the net effect is similar under GPL v2, but if the author stated “or any later version,” you are permitted to “upgrade” to GPL v3.

  • further - in the source when I modify existing files is there a convention for attributing work? Or just a general 'copyright me, some sections copyright him' type line at the top?
    – citronic
    Oct 17, 2012 at 22:32
  • 1
    the GPL (and even most BSD licenses) just say you have to both give credit, and take blame, if you will; if you just tweaked a few lines or added a certain feature, I'd suggest "Copyright 1974-2011 John Doe, Copyright 2012 Rutherford" and explain which bit(s) you've altered briefly. If it turns into more of a total rewrite or port, I usually put something like, "may contain code from..." or "based upon code from..." in a comment. I tend to think of it as the difference between attribution and plagiary.
    – BRPocock
    Oct 18, 2012 at 2:23

From your description, the answer is yes you would need to release the updated project under the GPL.

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