What are the "serious" libraries?

[Joe Nelson]

Fede Pereiro wrote:
> While not a library per se (it's a server), Redis provides well
> implemented data structures written in C.

Good point, I see a bunch of things in
https://github.com/antirez/redis/tree/unstable/src

Kind of wish they had released that part as a shared library that other
projects could use too. Not to say you couldn't just copy the sources
into your own project, but it would be nice to be able to install the
library with an OS package manager.