We welcome contributions big and small! The goal of BetterTLS is to add anything you think can of to improve the bettertls.com site or the ecosystem of TLS as a whole.
One of the easiest things you could do to get started is run one of the test suites against another TLS client. Check out nameconstraints/testsuites/runcurl.js and pathbuilding/impltests/curl_test.go for some simple examples of new test cases you can add.
If you'd like to extend BetterTLS with additional tests for one of the existing test suites or even develop test suites for some other TLS specification like HSTS or HPKP, we would love to include your contributions!
We don't have any strict requirements or procedures for contributing, so don't hesitate to open up a PR or issue!
If you would rather get in touch with us directly, feel free to email us at bettertls@netflix.com.