The development of Cask is at Github https://github.com/cask/cask. Development related discussion is done in a Google group https://groups.google.com/forum/#!forum/cask-dev.
Be sure to!
Implement the features and don't forget to test it. To run the tests, first start the fake ELPA server:
$ make start-server
To run the unit tests:
$ make unit
To run the integration tests:
$ make ecukes
And to run all tests:
$ make test
If all passes, send us a
pull request with the
changes. Note that we usually work on a WIP-branch, which is the
branch the pull request should target. They are named
v{MAJOR}.{MINOR}-wip. If no such branch exist, target the master
branch.