JSMN
jsmn (pronounced like 'jasmine') is a minimalistic JSON parser in C. It can be easily integrated into resource-limited or embedded projects.
You can find more information about JSON format at json.org
Library sources are available at https://github.com/zserge/jsmn
The web page with some information about jsmn can be found at http://zserge.com/jsmn.html
Philosophy
Most JSON parsers offer you a bunch of functions to load JSON data, parse it and extract any value by its name. jsmn proves that checking the correctness of every JSON packet or allocating temporary objects to store parsed JSON fields often is an overkill.
JSON format itself is extremely simple, so why should we complicate it?
jsmn is designed to be robust (it should work fine even with erroneous data), fast (it should parse data on the fly), portable (no superfluous dependencies or non-standard C extensions). And of course, simplicity is a key feature - simple code style, simple algorithm, simple integration into other projects.