This binary is a command-line wrapper for a library that implements JSON Schema draft 04 specification. It passes all the tests from https://github.com/json-schema/JSON-Schema-Test-Suite except for optional/bignum.json, but it doesn't mean that it's free of bugs, especially in scope alteration and resolution, since that part is not entrirely clear.
People who have agreed to the Cesanta CLA can make contributions. Note that the CLA isn't a copyright assigment but rather a copyright license. You retain the copyright on your contributions.
This software is released under commercial and GNU GPL v.2 open source licenses. The GPLv2 open source License does not generally permit incorporating this software into non-open source programs. For those customers who do not wish to comply with the GPLv2 open source license requirements, Cesanta offers a full, royalty-free commercial license and professional support without any of the GPL restrictions.