rxi-json-lua

- Implemented in pure Lua: works with 5.1, 5.2, 5.3 and JIT
- Fast: generally outperforms other pure Lua JSON implementations (benchmark scripts)
- Tiny: around 290sloc, 9kb
- Proper error messages, eg: expected '}' or ',' at line 203 col 30

See github readme for more information: https://github.com/rxi/json.lua/blob/master/README.md