c-ares is a C library for asynchronous DNS requests (including name resolves) :

Hiredis is a minimalistic C client library for the Redis database.

ldns The goal of ldns is to simplify DNS programming

libbsd library provides useful functions commonly found on BSD systems

libbpf Berkeley Packet Filter, is a generic kernel execution engine, allowed programmers to access low-level kernel functions more safely and easily.

LibElf is project implementing a BSD-licensed implementation of the SVR4 ELF(3) API.

libev A full-featured and high-performance (see benchmark) event loop

libevent is a software library that provides asynchronous event notification

libexpat This is Expat, a C library for parsing XML

libiconv library provides an iconv() implementation, for use on systems which don't have one

libmd library provides message digest functions found on BSD systems

libmnl is a minimalistic user-space library oriented to Netlink developers.

libnghttp3 is an implementation of HTTP/3 mapping over QUIC and QPACK in C. :

libngtcp2 project is an effort to implement RFC9500 QUIC protocol.

libsodium is a new, easy-to-use software library for encryption, decryption, signatures, password hashing and more.

libxml2 is an XML toolkit implemented in C, originally developed for the GNOME Project.

OpenSSL s a software library for applications that secure communications

OpenSSL Quic This fork can be used by QUIC implementations for connection handshake

protobuf are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data

protobuf-c, a C implementation of the Google Protocol Buffers data serialization format.

XZ Utils is free general-purpose data compression software with a high compression ratio