Open-source alternatives to Node V0.x Archive

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

Mio is a low-level I/O library for Rust that provides an event-driven framework for monitoring multiple network sockets and file descriptors. It acts as a portable wrapper for operating system native polling systems, including epoll, kqueue, and IOCP, allowing applications to trigger events when resources are ready for reading or writing without blocking the execution thread. The library provides a non-blocking socket interface for managing TCP, UDP, and Unix sockets. It distinguishes itself through a vectored I/O implementation, enabling scatter-gather reads and writes across multiple buffer

Handy is a C++11 network server framework and event-driven networking engine designed for building high-performance concurrent TCP and UDP servers. It functions as an asynchronous I/O library and an HTTP server implementation that separates asynchronous network I/O from synchronous business logic to simplify server development. The framework distinguishes itself by utilizing platform-specific event notifications to manage millions of simultaneous network connections and providing an SSL/TLS network wrapper for encrypted asynchronous data transmission. It implements a half-sync/half-async proc

ReactPHP is an asynchronous runtime and event-driven I/O framework for PHP. It provides an environment for executing concurrent tasks through a central event loop implementation and reactor pattern, allowing applications to handle multiple operations without pausing the main execution thread. The project includes a specialized asynchronous socket library for TCP, UDP, and TLS communication, alongside a non-blocking HTTP server and client for streaming web requests and responses. Its capability surface covers asynchronous control flow via promises and fibers, non-blocking network connectivity

Libevent is a cross-platform library that provides a mechanism for executing callback functions when specific events occur on file descriptors, signals, or timers. It functions as a network event loop framework, enabling the development of applications that manage concurrent network connections and non-blocking input and output operations within a single execution context. The library distinguishes itself by providing a portable abstraction layer that automatically selects the most efficient system-level event notification mechanism available on the host operating system. It includes thread-s

userver is a comprehensive C++ backend application platform and asynchronous framework designed for building scalable microservices. It provides a high-performance execution environment for deploying services that communicate via gRPC and HTTP using a middleware-based request pipeline. The platform distinguishes itself through a distributed service orchestration toolset that manages shared state, distributed locking, and dynamic configuration updates without requiring process restarts. It utilizes a coroutine-based asynchronous execution model and event-loop network I/O to handle high-concurr

Trio is an asynchronous I/O runtime and concurrency library for Python. It provides a system for executing non-blocking network and disk operations through a centralized event loop and task scheduler. The library is built on a structured concurrency model, which ensures that asynchronous tasks are bound to a specific lifetime and cannot outlive the scope that started them. It utilizes a nursery-based task manager to track task lifecycles in a parent-child tree, preventing orphaned concurrent operations by requiring child tasks to be joined before their parent scope exits. The framework cover

This project is a detailed analysis and study of the Nginx source code, focusing on high-performance server architecture and function call flows. It serves as a technical examination of the internal C implementation used to build high-concurrency networking systems. The project deconstructs the internal mechanisms of the web server, including the multi-process master-worker model, event-driven asynchronous I/O, and non-blocking socket communication. It analyzes the phase-based request processing lifecycle, from URI matching and header parsing to final content generation. The study covers a b

Swoole is a coroutine-based concurrency library and IO framework for PHP. It provides a system for building high-performance network servers and applications by bringing asynchronous, event-driven, and coroutine-based concurrency to the PHP runtime. The project distinguishes itself by implementing user-space coroutine scheduling and non-blocking IO interception, which transforms standard blocking network and file operations into asynchronous actions. It further enables high-speed data exchange across multiple PHP processes through shared memory management and specialized data structures. The

sslh is a network proxy that runs a single service listening on one port, inspects the first data packet of each incoming connection, and forwards the traffic to the appropriate backend based on the detected protocol. It acts as a protocol multiplexer, transparent TCP proxy, and UDP router, while also functioning as a privileged port manager and connection resource manager. By inspecting initial packets, sslh can distinguish protocols such as SSH, HTTP, TLS, and OpenVPN, routing each connection to the correct backend service from a single listen port. To operate efficiently without per-connec

Redis is a high-performance in-memory key-value store that functions as a distributed cache, message broker, and NoSQL database. It provides sub-millisecond read and write access to data stored in RAM and can operate as a vector database for indexing high-dimensional embeddings. The system supports a wide range of data storage and synchronization primitives, including the management of strings, hashes, lists, sets, and JSON documents. It enables real-time data operations through atomic transactions, hybrid persistence using snapshots and append-only logs, and high-availability configurations

Redisson is a Java library and Redis client that functions as a distributed Java object mapper, caching provider, and locking framework. It maps Java collections and concurrency primitives to distributed implementations backed by Redis and Valkey, providing synchronous, asynchronous, and reactive APIs for interacting with these data stores. The project distinguishes itself by providing a comprehensive suite of distributed coordination tools, including a locking framework for managing semaphores and countdown latches across multiple application nodes. It also serves as a distributed messaging

Drogon is a high-performance C++ HTTP web framework and asynchronous web server designed for building web applications and REST APIs. It utilizes an event-driven, non-blocking architecture to handle concurrent HTTP and WebSocket connections, and it implements a model-view-controller structure to separate business logic from presentation. The framework includes an integrated C++ object-relational mapping system and database client for performing asynchronous operations with relational databases and Redis key-value stores. It supports real-time, full-duplex communication via WebSockets and prov

Smol is a lightweight Rust asynchronous runtime and task executor. It provides a suite of foundational tools for scheduling and executing asynchronous futures, managing background workloads, and handling non-blocking network and file operations. The project includes a compatibility layer for adapting asynchronous types and execution contexts, enabling futures to run across different runtime ecosystems. It also features a mechanism to offload synchronous I/O and CPU-intensive operations to dedicated worker thread pools to prevent runtime stalls. Its capabilities cover non-blocking network I/O

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

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

h2o is a high-performance content delivery server and HTTP/3 web server. It functions as a network gateway and reverse proxy that forwards client requests to upstream servers to manage traffic flow and load. The project distinguishes itself as a protocol fuzzing tool, utilizing a testing framework to execute automated stress tests against network protocols to identify memory leaks and crashes. The server provides capabilities for secure web traffic management through encrypted data transmission and high-performance web serving across HTTP/1, HTTP/2, and HTTP/3. It includes tools for server r

HAProxy is a high-performance TCP and HTTP proxy that distributes traffic across multiple backend servers to ensure availability and fault tolerance for critical services. It operates in either TCP or HTTP mode, with an event-driven, single-threaded reactor that handles tens of thousands of connections without context switching, and supports kernel-level data transfer to minimize memory usage and latency. What distinguishes HAProxy is its configuration-file-first design, where all load-balancing rules and runtime behavior are defined in a declarative text file parsed at startup. It embeds a L

Sanic is a Python ASGI web framework and asynchronous HTTP server. It is designed to build high-performance web applications and servers that handle concurrent requests using non-blocking logic. The framework implements the Asynchronous Server Gateway Interface standard, allowing applications to be deployed across various ASGI-compatible servers. It utilizes an asyncio-based event loop and integrates a Cython-based runtime wrapper around libuv to manage I/O operations. The system manages traffic through route-based request dispatching and a middleware-based request pipeline. These components

EasySwoole is a high-performance asynchronous PHP framework designed for building event-driven networks and persistent memory applications. It functions as a toolkit for developing distributed microservices and asynchronous servers capable of handling concurrent HTTP, TCP, UDP, and WebSocket connections. The framework distinguishes itself through a persistent memory process execution mode that eliminates the overhead of repetitive file loading and invocation during request handling. It provides built-in support for distributed systems via remote procedure call implementations and service disc

CppGuide is a curated collection of educational resources and practical guides focused on C++ server development, Linux kernel internals, concurrent programming, network protocols, and security exploitation. It provides structured learning paths for backend developers, covering everything from interview preparation to building high-performance network servers and understanding operating system fundamentals. The guide distinguishes itself by offering in-depth, hands-on tutorials that walk through real-world implementations, including building a Redis-like server from scratch, designing custom

cppcoro is a C++ coroutine library and concurrency toolkit providing primitives for asynchronous tasks, lazy generators, and non-blocking execution. It functions as an asynchronous I/O framework for managing network sockets and file operations through an event loop. The library features a work-stealing thread pool for distributing tasks across multiple cores and a set of async generators for producing lazy sequences of values both synchronously and asynchronously. It includes a concurrency toolkit with async mutexes, latches, and shared tasks to coordinate multi-threaded execution. Its capab

Isolated-vm is a library for creating secure, memory-isolated JavaScript execution environments within Node.js. It functions as a manager for the underlying engine, allowing developers to instantiate multiple independent execution contexts that share no memory or global state. This architecture is designed to support the execution of untrusted third-party code while preventing interference with the main application process. The project distinguishes itself by enforcing strict resource constraints, including memory limits and CPU execution timeouts, to ensure host system stability. It provides

This project is a curated educational guide and instructional resource for the Node.js runtime environment. It serves as a comprehensive introduction to core concepts, including asynchronous programming tutorials, network application primers, and guides on the module system and stream API. The material focuses on the fundamental building blocks of server-side development, specifically how to create reusable code packages and manage project dependencies via a module manifest. It provides detailed instruction on building programs that communicate over HTTP and TCP protocols to exchange data acr

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

Drogon is a high-performance, cross-platform C++ framework designed for building asynchronous web services and server-side applications. It functions as a multi-threaded, event-driven server engine that manages concurrent network traffic and WebSocket connections with minimal latency. By leveraging non-blocking input/output and native code compilation, the framework provides a foundation for scalable applications that operate efficiently across diverse hardware architectures. The framework distinguishes itself through its compile-time template rendering, which transforms dynamic HTML views in

uvloop is a high-performance replacement for the standard Python event loop. It functions as a drop-in substitute designed to accelerate asynchronous networking tasks and reduce latency in event-driven software systems. The project achieves its performance characteristics by utilizing a Cython-based extension module that wraps the libuv C library. By leveraging low-level system calls for event-driven input and output multiplexing, it manages concurrent network requests and subprocess execution with minimal overhead. The implementation supports scalable backend service development by handling