Hello.

Here's a proposal to the census: zlib

Website (90s design, does it count as site?): http://zlib.net
Contributors: Only Madler (the famous Mark Adler from JPI's NASA)
since 2013. Before that, only occasional contributors appear.
Popularity: I'm not sure how to interpret that and there are many
similar packages, but the statistics show it's extremely popular.
Check it yourself https://qa.debian.org/popcon.php?package=zlib
Main Language: C.
Network Exposure: I think it does, as some network-based projects use
it. I'm sure more skilled people can look at that.
Repo: https://github.com/madler/zlib/
Dependencies: The list is absurdly enormous, even Linux kernel uses it.
Application Data Only: No idea how to look for that at Debian
Popularity Contest.
Patches: I've seen patches out there. There's a lot of forks and
unmerged pull requests too.
ABRT crash statistics: I have no idea of what is it.

Kind regards.