Boomerang's License

Why the change?

The original vision for Boomerang was somewhat different from what it turned out. There were high hopes that it would be quite usable by now, and that perhaps several commercial companies might like to incorporate the Boomerang engine into their product. For example, a disassembler like IDA Pro or Sourcer. However, this has not happened, so the advantage of a BSD-license (i.e. that it can be used as part of proprietary as well as free software) becomes moot.

Not releaseing Boomerang under the GNU General Public License becomes more and more difficult to sustain, because of all the highly useful GPL'd software that can't be used. One example is the GNU BFD library for reading executable, object, and library files. Hopefully soon, Boomerang will have signature generating and library function identifying software, and this is easier using the GPL'd BFD library. As you no doubt know, using GPL'd code in any body of code requires the whole body of code to be released under the GPL.

So soon, Boomerang will transition from a BSD-like license to a combined BSD-like license and the GPL. (Some existing code was written while the authors were working for Sun Microsystems, and that code must be used in conjunction with the BSD-like license.

How does Boomerang's new license work?

The requirements for both parts of the license are quite simple, and are readily combined. Basically, the restrictions are:
  • The file LICENSE.TERMS has to be distributed with the source code or binary distributions. This file is basically the combined original LICENSE.TERMS file with the GPL license file.
  • Source files with the Sun copyright notice must retain those notices.
  • Source files with the GPL notice must retain those notices.
  • Modifications to the source code and the binaries generated from them can be freely redistributed, as long as these conditions are met, and in addition the usual GPL conditions are met. In other words, the source code must be made available either from a web site (the Sourceforge project page satisfies this requirement), or otherwise the source code must be supplied on request by CD-Rom or the like.
  • If Boomerang code is used as part of another software project, that project must also be released under the terms of the GPL.
The overall effect is that some parts of the source code are released under the BSD-like license, others under the GPL, and the overall product is bound by the combination of the requirements of the two licences.

Last modified: 20/Sep/2005: Created