Open-source alternatives to RetroArch

Onion is a custom handheld gaming operating system and retro gaming frontend designed to manage and launch emulators on portable hardware. It functions as a bootable custom firmware distribution and emulation environment manager that replaces factory software to provide an integrated gaming environment. The system distinguishes itself through a modular core-based emulation architecture, allowing for the installation of verified emulator packages, BIOS configuration, and the use of hardware-specific drivers and filters. It also supports the integration of third-party game ports via standardize

Cemu is a cross-platform game console emulator designed to replicate the Nintendo Wii U hardware environment. It provides a software simulation layer that allows original Wii U games and homebrew applications to run on Windows, Linux, and macOS. The project translates guest machine code and graphics API calls into host instructions and modern shaders to enable hardware acceleration. It utilizes a dynamic recompilation engine and a host-API graphics backend to interface with Vulkan or OpenGL. The system manages hardware simulation through multi-threaded CPU emulation, memory-mapped I/O simula

Play- is a multi-system game emulator and virtual hardware emulator that simulates various console and arcade hardware to run original game files on modern devices. It functions as a retro game frontend, providing a graphical interface for organizing, launching, and managing libraries of legacy console and arcade titles. The project includes a hardware input mapper that translates modern controllers and mouse movements to simulate specialized legacy input devices, such as light guns and steering wheels. It also features a game state manager capable of capturing and restoring the exact memory

RetroPie-Setup is a specialized utility and installation tool designed to automate the orchestration of Linux-based retro gaming environments. It functions as a deployment system for configuring the dependencies and software required to run game libraries on single board computers, such as the Raspberry Pi and Odroid. The project provides a structured approach to deploying gaming emulators and managing RetroArch emulation cores. It includes a configuration tool for setting up graphical front ends that organize and launch emulated games across multiple systems. The tool handles system-level t

OptiScaler is a DirectX graphics middleware and temporal upscaler wrapper designed to intercept graphics API calls. It functions as a system for replacing native temporal anti-aliasing and upscaling technologies with alternative scaling methods and frame generation interop to improve resolution and performance. The project distinguishes itself by enabling modern high-resolution upscaling and frame generation in games built for legacy rendering standards. It includes a framework for importing low-latency graphics plugins and utilizes an interception layer to replace existing frame interpolatio

PyBoy is a programmable Game Boy emulator and hardware simulation framework written in Python. It functions as an emulation engine that allows users to execute original handheld software while providing a programmatic interface to control, probe, and automate game execution. The project is specifically designed as a reinforcement learning environment, exposing emulator states and controls to facilitate the training of machine learning agents. It distinguishes itself by providing tools for game area mapping and the extraction of simplified 2D screen representations and collision maps to suppor

Lemuroid is an Android multi-system emulator and Libretro frontend designed to run games from multiple vintage gaming systems through a single interface. It functions as a retro gaming library manager that scans local storage for game files and organizes them into a searchable catalog. The application includes a cloud-synced save manager to preserve game progress across different devices via remote storage. It also features a virtual gamepad interface that allows for custom input mapping across physical controllers, tilt sensors, and on-screen touch overlays. Additional capabilities cover ga

This is the original C source code for the Quake game engine, a landmark first-person shooter engine from the 1990s. It is a retro game engine that renders 3D environments and processes player input in real time using CPU-based software rendering rather than GPU acceleration. The engine supports networked multiplayer gameplay over LAN or internet connections and is designed to be moddable, allowing users to create and run custom game modifications and levels. The engine's architecture includes a Binary Space Partition tree for efficient world geometry organization and visibility determination

Craft is a multiplayer voxel sandbox written in C. It utilizes an OpenGL voxel engine to render a block-based world and implements an infinite terrain generator that uses noise functions to create deterministic, procedural landscapes. The project features a networked environment where players can build and modify a shared world using socket-based state synchronization. To maintain consistency across sessions, it employs a voxel world database to store and retrieve modified block coordinates. The system covers a range of capabilities including 3D collision detection for character movement, to

This project is a suite of runtime diagnostic tools designed to detect memory leaks, concurrency races, and language-specification violations during software execution. It provides a collection of dynamic analysis tools that identify addressability issues, uninitialized memory usage, and memory safety bugs in applications. The toolset includes a thread safety analyzer to identify data races and deadlocks in concurrent code, as well as an undefined behavior sanitizer to detect operations that violate language specifications. The system covers broad capabilities in memory safety monitoring and

C-code generator for docopt language.

gperftools is a collection of specialized tools for profiling CPU usage, detecting memory errors, and providing high-performance memory allocation. It provides a memory profiling toolkit for C++ applications, including a sampling CPU profiler and a heap profiler for analyzing consumption patterns. The project includes a high-performance memory allocator designed as a multi-threaded replacement for standard allocation to reduce contention and improve execution speed. It further provides a memory debugger to identify illegal memory access and double frees. The toolkit covers broad diagnostic c

This project is a cross-platform, open-source emulator designed to execute handheld gaming software on modern desktop and mobile hardware. By recreating the original console environment and system libraries, it allows users to run game files without requiring original firmware. The software achieves high-performance execution through a combination of dynamic recompilation and just-in-time instruction translation, which map console-specific instructions to native host machine code. The emulator distinguishes itself by providing advanced visual and connectivity enhancements that extend beyond t

libhv is a high-performance C/C++ network library and event-driven I/O framework used to build TCP, UDP, SSL, HTTP, WebSocket, and MQTT clients and servers. It provides a non-blocking event loop for managing network sockets, timers, and system signals across multiple threads. The project is distinguished by its integrated support for specialized network roles, including a full HTTP web server with RESTful routing and middleware, an MQTT messaging client for IoT communication, and the ability to implement SOCKS5 and HTTP proxies. It also features a reliable UDP implementation to ensure ordered

C library/compiler for the Cap'n Proto serialization/RPC protocol

NIH Utility Library

An implementation of the MessagePack serialization format in C / msgpack.orgC

💩 Colour ASCII Art Library

Parser combinators for binary formats, in C. Yes, in C. What? Don't look at me like that.

Gumbo-parser is a high-performance HTML5 parsing library written in pure C99. It transforms raw markup into a structured document tree by implementing the formal state-machine tokenization and error recovery rules defined in the HTML5 specification. The project serves as an HTML source mapping tool, linking parsed nodes back to their original byte offsets and pointers within the input buffer. This allows for the precise tracking of source locations for elements within the resulting parse tree. Beyond full document processing, the library handles isolated HTML fragments and provides a C-based

clib is a C language package manager and dependency manager used to install, update, and manage external C libraries and executable dependencies from remote repositories. It functions as a distribution tool for structuring source code and metadata to publish C libraries and a development toolkit for maintaining consistent build environments. The project provides a framework for C library distribution and dependency resolution, utilizing manifest files to track required library versions and ensure reproducible builds across different systems. It streamlines the C development workflow by managi

A protocol buffers library for C

Dolphin is a software environment that simulates GameCube and Wii console hardware, allowing users to execute game discs and digital software on modern computing platforms. It functions by translating original console processor instructions into native host machine code at runtime and intercepting low-level graphics commands to render them through modern graphics APIs. The project distinguishes itself through a comprehensive netplay engine that enables online multiplayer for local games by synchronizing game states and input timing across remote instances. This system enforces deterministic e

RabbitMQ C client

sds is a C dynamic string library that provides a memory management wrapper for heap-allocated strings. It implements binary-safe storage by tracking string lengths explicitly, allowing the library to handle null characters within data. The library distinguishes itself through a memory architecture that uses interchangeable function pointers for allocation and freeing, enabling the integration of custom memory managers. It utilizes header-stored length tracking to provide constant-time length retrieval and maintains null-terminated buffer padding to ensure compatibility with standard C string

Quake-2 is a game engine designed for the development of first-person shooters and the rendering of three-dimensional environments. It provides the core framework for processing real-time physics and player input within interactive 3D spaces. The engine supports software extensibility, allowing for the direct modification of source code to change gameplay mechanics and engine behaviors. This makes it a resource for retro game engineering and the study of early 3D development techniques. Its technical capabilities include vertex-based software rendering, BSP-tree spatial partitioning, and PVS