InterviewBit - A simple and easy to use online C++ compiler.
xtdstars128 - Modern C++17/20 framework to create console (CLI), forms (GUI like WinForms) and tunit (unit tests like Microsoft Unit Testing Framework) applications on Windows, macOS, Linux, iOS and android. [MIT]
djinni - A tool for generating cross-language type declarations and interface bindings. [Apache2]
Web Application Framework
Crowstars496 - Crow is a C++ microframework for running web services. It uses routing similar to Python's Flask. [BSD] website
dr_libsstars697 - Single file audio decoding libraries for C and C++. [Unlicense]
oneDALstars440 - A powerful machine learning library that helps speed up big data analysis. [Apache]
oneDNNstars2.5k - An open-source cross-platform performance library for deep learning applications. [Apache] website
PCG-rand - PCG is a family of simple fast space-efficient statistically good algorithms for random number generation. Unlike many general-purpose RNGs, they are also hard to predict. [Apache]
Indiesortstars8 - A sort wrapper which enables the use of std::sort (& other random-access sort functions) with non-random-access containers, and also improves sort performance for large/non-trivially-copyable types in random-access containers and arrays. [zLib] website
Dec 29th, 2020
concurrencppstars662 - A general concurrency library containing tasks, executors, timers and C++20 coroutines to rule them all.
KArchive - A library for creating, reading, writing and manipulating file archives like zip and tar. It also provides transparent compression and decompression of data, using formats like gzip, via a subclass of QIODevice. [LGPL]
jsonconsstars443 - A C++ header-only library for JSON and JSON-like binary formats with JSONPointer, JSONPatch, JSONPath and JMESPath. [Boost]
Aug 11th, 2020
PGM-indexstars553 - A data structure that enables fast lookup, predecessor, range searches and updates in arrays of billions of items using orders of magnitude less space than traditional indexes. [Apache2] website