Add license

Author: imax9000

LICENSE

@@ -0,0 +1,15 @@
+Copyright (c) 2015 Cesanta Software Limited
+All rights reserved
+
+This software is dual-licensed: you can redistribute it and/or modify
+it under the terms of the GNU General Public License version 2 as
+published by the Free Software Foundation. For the terms of this
+license, see <http://www.gnu.org/licenses/>.
+
+You are free to use this software under the terms of the GNU General
+Public License, but WITHOUT ANY WARRANTY; without even the implied
+warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+See the GNU General Public License for more details.
+
+Alternatively, you can license this software under a commercial
+license, as set out in <http://cesanta.com/>.

README.md

@@ -8,3 +8,23 @@ It passes all the tests from https://github.com/json-schema/JSON-Schema-Test-Sui
 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.
+
+## Contributions
+
+People who have agreed to the
+[Cesanta CLA](http://cesanta.com/contributors_la.html)
+can make contributions. Note that the CLA isn't a copyright
+_assigment_ but rather a copyright _license_.
+You retain the copyright on your contributions.
+
+## Licensing
+
+This software is released under commercial and
+[GNU GPL v.2](http://www.gnu.org/licenses/old-licenses/gpl-2.0.html) 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](http://cesanta.com) offers a full,
+royalty-free commercial license and professional support
+without any of the GPL restrictions.