GPL – How to Re-license BSD 2/3-Clause Code to GPL

bsd licensegpl

Suppose I release some source code under the new BSD license. Is it allowed for someone else to take this code, make modifications to it and distribute it under the terms of the GPL? From Wikipedia:

Many of the most common free software
licenses, such as the original MIT/X
license, BSD licenses (in the current
2-clause form), and the LGPL, are
"GPL-compatible". That is, their code
can be combined with a program under
the GPL without conflict (the new
combination would have the GPL applied
to the whole). However, some free/open
source software licenses are not
GPL-compatible.

I'm assuming this implies that one can relicense new-BSD licensed code to GPL?

Best Answer

That's an interesting question. Disclaimer: IANAL.

The quoted fragment means the BSD licensed code can be used in a project which is licensed GPL.

On the other hand, you're still the copyright holder of your code. The license of original code cannot be changed without your permission. Also BSD license explicitly requires:

  • Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
  • Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Thus BSD license cannot be stripped away from your code.

In order to actually be able to release combined code under GPL other author would have to make "significant contribution" to the code. It's vague what it exactly means, but usually should mean at least adding new significant feature, not just minor patch.

Similar situation: SFLC Completes Review of Atheros Wireless Driver for Linux, Releases Guide for Developers.

Related question on SO: https://stackoverflow.com/questions/821608/relicensing-a-bsd-library

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