PL/JSON is a JSON-implementation written in PL/SQL for Oracle. Since no bugs has been found in more than a month, I have changed the project status from beta to stable. The version remains to be 0.8.4 though.
The implementation got all the functionality I need, but if you want to put in other useful features, then please join the project and submit your changes. You could also just post your ideas in the open discussion forum: https://sourceforge.net/projects/pljson/forums/forum/935365.
You can download a copy at http://sourceforge.net/projects/pljson.
The license is MIT.