Open-source alternatives to Msquic

This project is a high-performance implementation of the QUIC transport protocol, providing a library for establishing multiplexed, low-latency network connections over UDP. It serves as a foundational networking stack for building modern web servers and clients, with native support for HTTP/3 and WebTransport standards. The library distinguishes itself through advanced connection management, including the ability to maintain stable sessions across changing network paths or IP addresses using connection identifiers. It optimizes data throughput by employing packet batching to reduce kernel ov

Proxygen is a collection of C++ libraries for building high-performance HTTP servers and clients. It provides a protocol parser that converts raw network bytes into high-level transaction objects and includes a network stack for processing web traffic over the QUIC transport protocol. The project implements a layered protocol abstraction and a QUIC-based transport integration to support multiple versions of the HTTP standard, including HTTP/3. It utilizes state-machine based parsing and an event-driven I/O loop to manage concurrent network connections. The library covers asynchronous buffer

KCP is a low-latency transport protocol and reliability layer designed to provide TCP-like guaranteed delivery and ordering over UDP. It implements an automatic repeat request protocol to minimize network jitter and delays, prioritizing timeliness over bandwidth efficiency. The project distinguishes itself through a pluggable congestion controller and flow control logic, allowing the transport layer to be tuned for specific network environments. It includes a NAT keep-alive system that uses periodic heartbeat packets to maintain active communication paths and prevent address translation timeo

kcp-go is a Go library implementing the KCP protocol for reliable data transmission over UDP. It provides a stream-based transport layer and an automatic repeat request network protocol to ensure ordered delivery while reducing network tail latency. The project differentiates itself through the use of forward error correction via Reed-Solomon codes to reconstruct lost packets without retransmissions. It also implements secure UDP tunneling by using block ciphers to encrypt both packet headers and payloads. The library includes capabilities for high-throughput networking through batch system

Netpoll is an event-driven network framework and non-blocking I/O library designed to manage concurrent TCP and Unix domain socket connections. It utilizes a non-blocking event loop to monitor file descriptors and trigger callbacks for read and write events, serving as a high-performance socket manager and TCP network poller. The framework optimizes throughput across CPU cores by distributing incoming network connections across multiple pollers. It implements zero-copy networking primitives, using linked buffers and specialized memory management to read and write data while minimizing memory

BBR is a TCP congestion control implementation designed to maximize throughput and minimize delay by modeling the network bottleneck. It functions as a network throughput optimizer that adjusts data transfer speeds based on estimated bottleneck bandwidth. The project includes a network condition emulator to simulate packet loss and latency for testing transport protocol performance. It also provides a performance analysis toolset for monitoring connection states and visualizing congestion control behavior. The system covers broader capabilities in network performance analysis, connection sta

libmodbus is a portable C library that implements the Modbus protocol stack for industrial hardware communication. It provides a set of tools for reading and writing coils and registers on industrial controllers and sensors, functioning as both a client and a protocol server. The library supports multiple transport layers, including a Modbus TCP stack for IPv4 and IPv6 network communication and a Modbus RTU driver for serial communication. It distinguishes itself through specialized data conversion utilities that handle byte-swapping and endianness for floating-point numbers and bit-field map

f-stack is a kernel-bypass framework and user-space TCP/IP stack designed to increase packet processing speeds and overall throughput. It utilizes DPDK to route network traffic directly to user space and integrates a transplanted FreeBSD network stack to handle transport and network layer protocols outside of the host operating system. The project provides a socket API compatibility layer that allows standard network applications to run on a high-performance backend without requiring code changes. It also features a coroutine-based network API and micro-threading interface to manage asynchron

Memcached is a high-performance, distributed, in-memory key-value storage and request routing engine. It functions as a volatile data store designed to accelerate dynamic applications by caching objects in RAM, thereby reducing backend database load and providing sub-millisecond response times. The system utilizes a specialized architecture that organizes memory into fixed-size slabs to minimize fragmentation and maximize throughput for high-concurrency workloads. The project distinguishes itself through a multi-threaded, lock-friendly design that scales across CPU cores and supports complex

Vector is a high-performance observability data pipeline designed to collect, transform, and route logs, metrics, and traces across distributed infrastructure. It functions as a modular engine that decouples data ingestion from processing and transmission, utilizing a component-based architecture to connect diverse sources to multiple destinations. The project distinguishes itself through a focus on reliability and flow control. It implements backpressure-aware data movement to prevent data loss during traffic spikes and utilizes disk-backed event buffering to ensure durability during network

Synapse is a Matrix homeserver implementation that provides the infrastructure for decentralized, real-time communication and messaging. It functions as a federated chat server that synchronizes room data and event streams across independent server instances to enable cross-domain interoperability. The server utilizes a hybrid core that integrates performance-critical logic in Rust with a Python orchestration layer. It employs a PostgreSQL relational database for persisting user accounts and conversation history, and uses a Redis-based messaging system to distribute tasks across horizontal wo

The Kubernetes Python Client is a programmatic interface for cluster automation and resource management. It provides a REST-based API client that maps method calls to HTTP verbs and JSON payloads to create, update, delete, and monitor workloads and infrastructure components. The client features dynamic schema mapping and resource mapping, allowing it to control custom objects and unique resource definitions without requiring pre-defined classes or static schemas. It supports YAML manifest parsing to convert structured files into compatible objects for bulk resource deployment. The toolset co

NGINX Unit is an open-source application server designed to natively execute code across multiple programming language runtimes and WebAssembly within a single process. It serves as a multi-language application server that can run applications written in Go, Java, Node.js, Perl, PHP, Python, Ruby, and WebAssembly side by side, without requiring separate runtime environments for each language. The server distinguishes itself through a RESTful JSON control API that enables dynamic, zero-downtime configuration changes without restarting the server. It combines event-driven asynchronous I/O with

Quarkus is a Kubernetes-native Java framework designed for building high-performance, memory-efficient applications. It utilizes ahead-of-time native compilation to transform Java code into standalone, optimized binaries that eliminate the need for a virtual machine, enabling rapid startup and reduced memory consumption. By performing code augmentation during the build phase, it shifts heavy processing tasks away from runtime, ensuring that applications are optimized for cloud-native environments. The framework distinguishes itself through a unified approach to reactive and imperative program

GameNetworkingSockets is a UDP networking library providing secure transport, peer discovery, and traffic control systems. It implements a networking layer for reliable and unreliable messaging over UDP, including tools for message fragmentation and reassembly. The project features a peer-to-peer NAT traversal tool for establishing direct host-to-host connections by punching through firewalls and network address translation layers. It secures network traffic through encrypted transport and secure key exchange. The library includes a traffic manager to organize data into prioritized lanes to

Aeron provides infrastructure components for high-speed inter-process and network communication, archiving message streams, and coordinating replicated services. It functions as a system for moving data between remote applications or local processes with low latency and high throughput. The project distinguishes itself through a combination of shared memory for ultra-low latency inter-process communication and a reliable UDP messaging transport that supports both unicast and multicast. It further includes a consensus-based service orchestrator to maintain consistency across replicated state m

This is a header-only C++ library that provides implementations for HTTP clients, HTTP servers, and a WebSocket framework. It allows for the creation of network services and the consumption of remote APIs without requiring a separate compilation step or external binary linking. The project features backend-agnostic TLS integration for secure HTTPS and WSS communication and employs a thread-pool model to process concurrent requests. It distinguishes itself with a full-duplex WebSocket state-machine and a middleware-based request pipeline that supports regular-expression path routing. The libr

libtorrent is a portable C++ library that implements the complete BitTorrent protocol for peer-to-peer file transfers, supporting distributed hash tables (DHT), magnet links, and protocol extensions. It provides a well-documented C++ interface for building custom BitTorrent clients with full protocol support, handling peer communication, piece management, and swarm coordination. The library includes a comprehensive set of protocol components, including peer wire protocol encoding, piece-picking scheduling using rarest-first algorithms, session-based connection management for TCP and uTP conne

This project is a full-featured BitTorrent client library and protocol implementation. It provides the core components necessary for peer-to-peer file sharing, including a networking stack that supports the BitTorrent specification, tracker communication, and swarm management. A primary differentiator is the inclusion of a virtual filesystem that allows torrents to be mounted as read-only drives. This system enables on-demand content streaming, where specific data pieces are fetched from the network only when a read request occurs, rather than requiring the entire archive to be downloaded fir

tbox is a multi-platform C standard library and toolkit designed for portable software development. It provides a core foundation for low-level system programming through a collection of system primitives, data structures, and memory management tools. The project includes a coroutine framework for cooperative multitasking and asynchronous logic, a data structure library featuring generic containers with a consistent iterator interface, and a memory management toolkit for pool allocation and debugging of heap overflows and leaks. It also provides a network and serialization toolset for handlin

cpr is a C++ networking library that provides a high-level HTTP request client. It functions as a wrapper around libcurl to simplify the process of sending and receiving data from web servers, specifically managing GET and POST calls and multipart form uploads. The library provides both synchronous and asynchronous execution models, allowing network requests to run on background threads to prevent application freezing. It integrates with the C++ Standard Library to map low-level pointers to standard strings and containers, utilizing RAII for automatic resource management. The project covers

Muduo is a C++11 event-driven network library and framework designed for building high-concurrency Linux servers. It provides a toolkit for implementing scalable network services and socket communication using non-blocking I/O and asynchronous event processing. The framework implements a multi-threaded TCP server architecture that distributes connection handling across multiple CPU threads to maximize server throughput. This is achieved through a one-loop-per-thread model and a reactor pattern implementation, which dispatch network events from a central demultiplexer to registered handler fun

This project is a collection of single-header libraries providing a zero-dependency implementation of core game engine systems. It serves as a portable toolkit for 2D game development, focusing on asset loading, graphics optimization, and low-level system coordination. The libraries offer specialized capabilities for 2D sprite rendering and asset processing, including texture atlas compilation and batch-based rendering to reduce draw calls. It includes a dedicated pipeline for parsing Aseprite files and JSON-formatted map data from Tiled. The toolkit covers several functional domains, includ

Tbox is a comprehensive collection of low-level utility libraries and toolkits for portable C development. It provides a multi-platform C utility library that serves as a lightweight replacement for standard libraries, offering optimized memory management and system abstractions to ensure hardware compatibility across different operating systems. The project distinguishes itself through a specialized framework of standardized data containers, including hash tables, vectors, and linked lists with integrated searching and sorting. It further provides a dedicated toolkit for networking and seria

ChartMuseum is a centralized server for hosting, versioning, and distributing Kubernetes package repositories. It functions as a Kubernetes package manager and an OCI compatible registry, providing a system to manage the full lifecycle of software artifacts from upload and versioning to verification and deletion. The project supports multitenant repository hosting by organizing packages into isolated namespaces for different teams and organizations. It utilizes a storage abstraction layer that allows packages to be persisted to local filesystems or S3 compatible cloud object stores, including

GSConnect is a GNOME Shell extension that implements the KDE Connect protocol to synchronize notifications, files, and clipboard data between a desktop and a mobile device. It serves as a cross-device synchronization tool and wireless file transfer utility, allowing for the mirrored exchange of system states and data over a local network. The project enables remote device control, allowing a connected phone to manage a computer's media playback, adjust system volume, and operate the host cursor and keyboard. It also functions as a remote device controller for triggering phone actions, such as

This project provides the formal network protocol standards and technical specifications for HTTP/2. It defines the requirements for binary framing structures, the HPACK compression standard for header fields, and the general behaviors necessary to ensure consistent data exchange and interoperability between network clients and servers. The specification covers the mechanisms for binary frame multiplexing and the HPACK standard to reduce network bandwidth and latency. It details the rules for session establishment, including connection preface handshaking and protocol negotiation. The projec