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 20161109.21 (version 21: Nov 9, 2016)
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.)