Eli Zaretskii <eliz@gnu.org> schrieb am Mo., 18. Sep. 2017 um 16:58 Uhr:

> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Mon, 18 Sep 2017 13:26:34 +0000
>
> I've discovered that the interface and documentation of Jansson are much better than the ones of json-c, so I
> switched to Jansson.

Thanks, but isn't Jansson less actively developed, judging by your
survey?

A bit, but it did have a nonzero number of commits in the last month, and over a longer term seems quite active. (Some of the other libraries had their last commit in 2014.)

> I've attached a patch.

I thought we wanted to import the library into Emacs proper, didn't
we? What is the purpose of providing such a core functionality as an
optional feature?

If we want to make it mandatory, we can always make the library mandatory and/or include its source code. However, the latter has significant downsides (we need to maintain the source code), so I don't think we should do it, at least not in the first iteration. For now, we can define the new functions in json.el if native support isn't available.