PL/JSON is a generic JSON object written in PL/SQL. Using PL/SQL object syntax, users instantiate a JSON object and then add members, arrays and additional JSON objects. This object type can store JSON data, in Oracle, persistently.
PLSQL PLpgSQL SQLPL JavaScript
Latest commit be08929 Apr 24, 2016 @jsumners jsumners Merge pull request #45 from dsnz/master
fix for issue #44 (missing json elements in parsed text for pljson_table)

readme.txt

This software has been released under the MIT license:

  Copyright (c) 2009 Jonas Krogsboell and Lewis R Cunningham

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.

Installation:

1.  To install, extract the files to a directory
2.  change to the directory where the files exist
3.  run the install.sql file 
4.  To test the implementation, run the /testsuite/testall.sql file
5.  To learn the API, look at the files in /examples

General information about JSON is available at http://www.json.org