Godot Engine – Multi-platform 2D and 3D game engine

JSON for Modern C++

A modern, C++-native, test framework for unit-tests, TDD and BDD - using C++14, C++17 and later (C++11 support is in v2.x branch, and C++03 on the Catch1.x branch)

Cocos2d-x is a suite of open-source, cross-platform, game-development tools utilized by millions of developers across the globe. Its core has evolved to serve as the foundation for Cocos Creator 1.…

Reliable & unreliable messages over UDP. Robust message fragmentation & reassembly. P2P networking / NAT traversal. Encryption.

A lightweight, fast and extensible game server for Minecraft

Command and Conquer: Generals - Zero Hour

Doom 3 GPL source release

CLI11 is a command line parser for C++11 and beyond that provides a rich feature set with a simple and intuitive interface.

fheroes2 is a recreation of Heroes of Might and Magic II game engine

A network library for client/server games written in C++

UTF-8 with C++ in a Portable Way

rpclib is a modern C++ msgpack-RPC server and client library

C++ compile-time enum to string, iteration, in a single header file

Library to parse and work with the C++ AST

A high performance, middleware oriented C++14 http web framework please use matt-42/lithium instead

Official repository of the SOCI - The C++ Database Access Library

std::tuple like methods for user defined types without any macro or boilerplate code

The Domain-Correct Quantities and Units Library for C++ — full quantity kind safety, ISO 80000 compliant, C++29 standardization candidate.

Axmol – A Multi-platform Engine for Desktop, XBOX (UWP), WebAssembly and Mobile games.

The official C++ client API for PostgreSQL.

easy to use, powerful & expressive command line argument parsing for modern C++ / single header / usage & doc generation

C++ library for Telegram bot API

C++ game engine for Windows, macOS, Linux, iOS, tvOS, Android, and web browsers

The C++14 wrapper around sqlite library

A C++17 cross-platform implementation for UUIDs

Edyn is a real-time physics engine organized as an ECS.

a header-file-only, SHA256 hash generator in C++

A C++11 RESTful web server library

Header-only C++11 library to encode/decode base64, base64url, base32, base32hex and hex (a.k.a. base16) as specified in RFC 4648, plus Crockford's base32. MIT licensed with consistent, flexible API.