I've coded up some simple JSON encode/decode routines in pure Lua and thought I'd share them in case anyone else would find them useful. I use them in Adobe Lightroom, but they're pure Lua 5, so can be used anywhere Lua is.
Version 20141223.14 (version 14: Dec 23, 2014)
Full docs and changelog are in the code itself, but basic use is:
(You might also be interested in this comparison of Lua JSON packages.)