For developers, who are building real-time data-driven applications, Redis is the preferred, fastest, and most feature-rich cache, data structure server, and document and vector query engine.

Modern HTTP benchmarking tool

stb single-file public domain libraries for C/C++

A code-searching tool similar to ack, but faster.

UNIX-like reverse engineering framework and command-line toolset

VLC media player - All pull requests are ignored, please use MRs on https://code.videolan.org/videolan/vlc

SumatraPDF reader

A single-header ANSI C gui library

AddressSanitizer, ThreadSanitizer, MemorySanitizer

darktable is an open source photography workflow application and raw developer

H2O - the optimized HTTP/1, HTTP/2, HTTP/3 server

Simple and portable (but not inflexible) GUI library in C that uses the native GUI technologies of each platform it supports.

A single-header ANSI C immediate mode cross-platform GUI library

minimal cross-platform standalone C headers

http://torch.ch

Samples for CUDA Developers which demonstrates features in CUDA Toolkit

A fast entity component system (ECS) for C & C++

πfs - the data-free filesystem!

3D engine with modern graphics

Static recompilation of Majora's Mask (and soon Ocarina of Time) for PC (Windows/Linux/Mac)

A native, user-mode, multi-process, graphical debugger.

Antialiased 2D vector drawing library on top of OpenGL for UI and visualizations.

Lightweight Ruby

The Foundation Project, providing core utilities, internationalization, and OS independence

Lightweight automation and productivity app for OS X

The seL4 microkernel

A tiny immediate-mode UI library

Package manager for the C programming language.

The safe Markdown parser, reloaded.

A standalone and lightweight C library