In an ideal world, we wouldn't have to apply copyright to API interfaces at all, but with a precedent set by the Federal Court, in the Oracle v Google case, a proactive stance is needed. API Commons is looking to provide a common place, where API designers can find, and publish API definitions that are openly licensed using Creative Commons licenses.
API Commons supports two of the most liberal Creative Commons licenses:
API Commons feels that it is critical, for the API interface layer remain openly licensed, interoperable, and re-usable, even for commercial purposes, for all of this to work. Without the ability to reuse, borrow, and share the best of breed API patterns the API economy will never reach its full potential.
Once you have added the API Commons manifest for your API, applying one of the licenses above, you are welcome to us the API Commons icon, on your website, and API Commons will work with API directories and search engines to showcase your APIs as "In The API Commons".