Tup is dual-licensed; as such, you are able to choose which set of terms apply for you to use and distribute tup. You can use and distribute it freely under the GPL-v2 license, or choose a commercial license for distribution with a closed-source program (such as a commercial IDE).

Option 1: GPL-v2

Tup is available under the GPL-v2 license. See the tup/COPYING file for the actual license. In general, with the GPL-v2 license:

Option 2: Commercial

There is no single commercial license for tup. A commercial license is available for those wishing to include tup in a larger work, but where releasing all parts of the larger work under the GPL is not feasible. The terms and conditions for such a license are determined on a case-by-case basis. For more information, please contact Mike Shal - you can find my email in the git log.

Contributor License Agreement

Due to the dual-licensed nature of tup, contributors are asked to sign a Contributor License Agreement (CLA) and send it to the project owner. Such contributions (ie: patches sent to the mailing list, branches made available on GitHub, etc) will be made freely available under the GPL-v2 license, and may also be made available under commercial licenses. The CLA is located here: icla.txt

Third-party Libraries

Tup is distributed with several third-party utilities and libraries. These are licensed as follows: