Version 1 (modified by fpierfed, 11 years ago) (diff)



LSST as a project has a desire to publish all its software as open source. There are a multitude of open source/free software licenses to choose from. At the same time, LSST has a few additional requirements/desiderata to take into consideration when choosing the "right" license:

  • Acknowledge and credit authorship, but do not retain ownership
  • Allow but not encourage commercial use
  • Preserve all non-commercial use

Another issue to take into consideration, apart from the specific license to use, is that of copyright.


Given all the above, the Apache License 2.0 appears to be a good fit. It allows users of Apache licensed software to

  • Copy, distribute, modify the software
  • Exercise patent rights on the portions of licensed software that they use and that would normally only be the right of the licensor

At the same time, the Apache license requires that

  • All copies, modified or unmodified, are accompanied by a copy of the licence
  • All modifications are clearly marked as being the work of the modifier
  • All notices of copyright, trademark and patent rights are reproduced accurately in distributed copies
  • The licensee does not start legal action against the licensor(s) over patent infringement
  • The licensee does not use any trademarks that belong to the licensor

It is useful to note that software distributed under the Apache license 2.0 is provided as is (i.e. without any warranty of any sort).

Further Resources

  1. OSS Watch discussion of the Apache License 2.0
  2. Wikipedia Article on Apache License 2.0