No, I haven't seen that one (looks like you wrote it?). I was looking for them at the tail end of 2011 and it looks like json-parser came into existence in march, 2012.

json-parser, at first glance, appears to be nice, too. The ones I looked at before were all multiple files and seemingly very complicated--either to use or to build/integrate with my code. I'll keep a pointer to this one too for when I get back on that project.