ke, conan   
[ libnavajo ](https://github.com/titi38/libnavajo) |  A C++ framework including a fast multithreaded http server, HTML5 Websockets, SSL, X509 and HTTP authentification, compression, cookies and advanced session management, IPv4 and IPv6 (CeCILL-C).  |  CeCILL-C FREE SOFTWARE LICENSE AGREEMENT  |  cmake   
[ libtins ](https://libtins.github.io/) |  A network packet crafting and sniffing library ( [ Src ](https://github.com/mfontanini/libtins) ) ( [ Doc ](https://libtins.github.io/docs/latest/) )  |  BSD-2  |  cmake, vcpkg   
[ LiteNetLibPP ](https://github.com/Revan600/LiteNetLibPP) |  A lightweight reliable UDP library for games  |  MIT  |  cmake   
[ mailio ](https://github.com/karastojko/mailio) |  MIME and email library  |  BSD 2-Clause "Simplified"  |  cmake   
[ nanomsg ](https://nanomsg.org/) |  A fast message queue, zeromq successor  |  |   
[ netif ](https://github.com/gmlc-tdc/netif) |  A C++14 library for getting network addresses on Windows, Linux, macOS, and FreeBSD.  |  BSD 3-Clause "New" or "Revised"  |  header-only; cmake   
[ nghttp2 ](https://github.com/nghttp2/nghttp2) |  HTTP/2 C Library and tools (server, client, proxy and benchmarking tools)  |  MIT  |  cmake, configure   
[ ngrest ](https://github.com/loentar/ngrest) |  A fast and easy in use JSON RESTful Web Services Framework  |  Apache 2.0  |  cmake   
[ nng ](https://nng.nanomsg.org/) |  A fast message queue, nanomsg successor  |  |   
[ Oat++ ](https://oatpp.io/) |  A Web Framework: REST-API and Request implementation ( [ Src ](https://github.com/oatpp/oatpp) ) ( [ Doc ](https://oatpp.io/docs/start/) )  |  Apache 2.0  |  cmake   
[ omniORB ](http://omniorb.sourceforge.net) |  The fastest, complete and portable CORBA ORB implementation in C++  |  |   
[ OpenDDS ](https://www.opendds.org) |  DDS (Data Distribution Service) implementation  |  |   
[ Paho MQTT ](https://github.com/eclipse/paho.mqtt.cpp/) |  A modern C++ client for MQTT from Eclipse  |  |  cmake   
[ paozhu ](https://github.com/hggq/paozhu) |  A C++20 Web Framework Support HTTP/2 ORM WebSocket  |  MIT  |  cmake   
[ PcapPlusPlus ](https://seladb.github.io/PcapPlusPlus-Doc/) |  Multi-platform C++ network sniffing and packet parsing and crafting framework. Provides C++ wrappers for many popular packet processing engines such as libpcap, Npcap, WinPcap, DPDK, AF_XDP, and PF_RING. ( [ Src ](https://github.com/seladb/PcapPlusPlus) )  |  [ Unlicense ](https://github.com/seladb/PcapPlusPlus#Unlicense-1-ov-file) |  conan, homebrew, cmake, vcpkg   
[ POCO ](https://pocoproject.org/) |  Networking: encryption, HTTP; Zip files ( [ Doc ](https://pocoproject.org/documentation.html) )  |  |   
[ rest_rpc ](https://github.com/qicosmos/rest_rpc) |  A C++11, high performance, cross-platform, easy to use RPC framework.  |  MIT  |  cmake   
[ restbed ](https://github.com/corvusoft/restbed) |  A cross-platform feature rich framework brings asynchronous RESTful functionality (secure communication over HTTP) to C++14 applications.  |  [ License ](https://github.com/Corvusoft/restbed/blob/master/LICENSE) |  cmake   
[ restc-cpp ](https://github.com/jgaa/restc-cpp) |  Accessing JSON API's from C++. HTTP Client, native C++ class to/from JSON serialization, asynchronous IO trough boost::asio coroutines. C++14.  |  MIT  |  cmake   
[ restful_mapper ](https://github.com/logandk/restful_mapper) |  ORM for consuming RESTful JSON APIs in C++  |  |  cmake, make   
[ seastar ](https://github.com/scylladb/seastar) |  A high performance server-side application framework, based on C++14/C++17.  |  Apache 2.0  |  cmake, etc.   
[ Silicon ](https://siliconframework.org) |  The Silicon C++14 Web Framework: Fast and Robust Web APIs  |  MIT  |  cmake   
[ sockpp ](https://github.com/fpagliughi/sockpp) |  A simple, modern C++ socket library  |  BSD 3-Clause "New" or "Revised"  |  cmake   
[ stream-client ](https://github.com/TinkoffCreditSystems/stream-client) |  A lightweight Boost-based client-side socket/connector