С++

С++ online

The collaborative browser based IDEreplit

Compiler ExplorerCompileExplore

Quick C++ BenchmarksFredTingaudDev

C++ Build BenchmarksFredTingaudDev

Online C++ Compiler - online editorGDB online Debugger

C++

homeCMake

Ninja, a small build system with a focus on speed

Conan.io - the Open Source C/C++ Package Manager for Developers

JFrog ConanCenter - The Central Repository for C / C++ packages

Boost C++ Libraries

A list of open source C++ libraries - cppreference.com

Protocol Buffers  |  Google DevelopersGoogle Developers