ujson is an ultra fast JSON encoder and decoder written in pure C (as described by the upstream). It can be used as dropin replacement of the most known JSON implementations.
To install you just do:
$ pip install ujson
To test the speed I decided to write two simple test scripts with help from timeit_ module.
The execution:
$ python json_test.py
5.39651107788
$ python ujson_test.py
1.09844493866
Review request for the Fedora package is already filled.