The not so great automatic Haskell licensor
Licensor is a program that generates a report of the dependencies and
transitive dependencies of a Haskell project and their licenses.
NOTE: Currently, Stack and a
stack.yaml file are
Choosing a license for a software project or determining whether a
particular dependency can be added to a project can be projects
themselves. Unless starting from scratch, programmers should consider
the licenses of the dependencies and transitive dependencies of their
projects to make informed decisions and avoid license compatibility
Of course, this is just a starting point. "Beyond (...) general
observations, it is difficult, if not impossible, to provide precise
guidance about what licenses may or may not be compatible with each
other. (...) Programmers who are considering combining code governed
by two or more different licenses should proceed cautiously" (Andrew
M. St. Laurent).
Licensor is not a lawyer and does not provide legal advice.
For more information about licenses and license compatibility issues,
read the text of the licenses or consult with a lawyer before making
Licensor is not the only license compatibility helper for Haskell:
- Licensor uses a Cabal library and Stack program approach for
detecting licenses and listing dependencies, respectively. For a
Cabal library and program approach, consider using
the cabal-dependency-licenses program or the cabal-plan
Installation and usage
To install Licensor, use Cabal:
$ cabal update && cabal install licensor
Then, run the
licensor executable inside a Haskell project:
To see the license report for Licensor, clone the repository:
$ git clone https://github.com/jpvillaisaza/licensor
licensor inside the project:
$ cd licensor/ && licensor
Or build and run
licensor inside the project:
$ cd licensor/ && stack build --exec licensor
To generate a report including license files for all dependencies,
--licenses option and redirect the output to a file:
$ licensor --quiet --licenses > licenses.md
See licenses.md for an example.
NOTE: This is currently using the Hackage API, which doesn't require
building any package, but could probably be improved to use the
installed packages if present.
For more information, run
-q, -s --quiet, --silent Quiet/silent mode
--licenses Fetch license files
-h --help Display help message
-V --version Print version information
Licensor uses the Stack program to list dependencies for a Haskell
project. A future enhancement could be to use the Stack library.
Licenses and license detection
Licensor uses the Cabal library to detect the license of a Haskell
project and its dependencies (including transitive dependencies). To
do so, it uses the license field in the package description. A future
enhancement could be to use both the license and licence file fields
in the package description.
Cabal provides an enumeration of common open source and free software
licenses. These are the licenses that appear in the reports generated
||GNU General Public License
||GNU Affero General Public License
||GNU Lesser General Public License
||BSD 2-Clause License
||BSD 3-Clause License
||BSD 4-Clause License
||Mozilla Public License
||All rights reserved
||Unspecified license (All rights reserved)
Feel free to create issues for reporting bugs and suggesting
enhancements, or to fork the repository and open a pull request.
Licensor is licensed under the MIT License.
Licensor (0.5.0) depends on the following libraries:
And the following licenses (including transitive dependencies):
||Number of libraries
(Tested with Licensor 0.5.0, Stack 2.7.1, and LTS Haskell 17.13.)