Open-source alternatives to ESPAsyncWebServer

Evio is a high-performance networking library for Go that provides a non-blocking socket framework. It utilizes an event loop to process TCP, UDP, and Unix domain socket traffic through a low-level asynchronous protocol interface. The project functions as a multi-core network load balancer, distributing connections across multiple CPU cores using round-robin or least-connections strategies. It supports socket reuse, allowing multiple sockets on a single host to bind to the same port. The library covers a broad range of socket management and packet processing capabilities, including multi-pro

evpp is a C++ network library and framework designed for building high-performance network services using TCP, UDP, and HTTP protocols. It provides an asynchronous event loop to manage nonblocking I/O operations and concurrent network connections across multiple threads. The framework includes specialized tools for asynchronous DNS resolution and a system for asynchronous task scheduling using a managed thread pool. It also features a nonblocking HTTP server and client with integrated connection pooling. The project covers low-level transport layer connectivity for TCP and UDP, as well as hi

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

GCDWebServer is a lightweight HTTP 1.1 server for iOS, macOS, and tvOS. It serves as an embedded network server for Apple platforms, allowing developers to handle incoming requests through custom synchronous or asynchronous handlers. The project includes a WebDAV server implementation for remote file management, directory browsing, and synchronization using standard network clients. It also provides a web-based file manager that enables users to upload, download, and organize files within an application sandbox via a browser. Additional capabilities include gzip compression, JSON processing,

This library provides a framework for building event-driven, non-blocking network applications in PHP. It enables the development of asynchronous TCP and TLS servers and clients that manage multiple concurrent connections without stalling the main execution thread. By utilizing an event-loop architecture, the library handles network operations and data exchange through asynchronous streams, ensuring that the application remains responsive during high-throughput tasks. The project distinguishes itself through its integration with operating system primitives, such as raw file descriptors and Un

shadowsocks-libev is an event-driven network daemon that provides an encrypted SOCKS5 proxy. It functions as a lightweight proxy server using a non-blocking event loop to route TCP and UDP traffic through encrypted tunnels to bypass network restrictions. The project implements a transparent proxy gateway capable of intercepting outbound packets at the network layer, allowing system traffic to be redirected through the encrypted tunnel without per-application configuration. It also includes a daemon process manager to control multiple proxy server instances as child processes via local communi

uWebSockets is a C++ networking framework that serves as a high-performance WebSocket server library, HTTP web server, and pub-sub messaging system. It provides the infrastructure necessary to handle standard web requests and maintain low-latency, bidirectional connections between clients and servers. The framework is distinguished by its use of template meta-programming for compile-time optimization and zero-copy buffer management to minimize memory latency. It utilizes a backend-agnostic event loop and static route resolution to process network traffic with minimal runtime overhead. The pr

Gevent is a Python coroutine concurrency library and asynchronous task manager designed for high-concurrency I/O tasks. It provides a cooperative networking framework for building asynchronous TCP, UDP, and HTTP servers, as well as a WSGI web server implementation for hosting web applications. The project is distinguished by its standard library monkey-patching tool, which replaces blocking synchronous functions with cooperative versions to enable asynchronous behavior in third-party code. This allows for a cooperative multitasking workflow where the system yields execution during I/O waits t

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

Ratchet is a PHP library for building asynchronous WebSocket servers that handle persistent, bidirectional communication between clients and the server. It provides a complete server-side WebSocket implementation, including protocol handshake negotiation, message framing over TCP, and an event-loop-based concurrency model that manages thousands of simultaneous connections without blocking. The library implements a connection registry pattern for tracking all active WebSocket sessions, enabling the server to broadcast or unicast messages to any connected client on demand. It relies on non-bloc

Salvo is a comprehensive Rust web framework for building asynchronous HTTP servers and web applications. It features a hierarchical web router that uses a tree-based structure to map requests to handlers and an asynchronous middleware pipeline based on the onion model for request and response pre- and post-processing. The framework is distinguished by its native support for modern network protocols, including a QUIC-based HTTP/3 implementation alongside HTTP/1 and HTTP/2. It includes an integrated OpenAPI documentation generator that extracts schemas directly from handler signatures to produc

Vibora is an asynchronous Python web framework and built-in HTTP server designed for building high-performance web applications. It utilizes an asynchronous event loop and coroutines to process network requests and serve responses without requiring external server wrappers. The project features a high-performance asynchronous schema validator for request integrity, a non-blocking template engine with support for hot-reloading, and a WebSocket communication server for bidirectional real-time data exchange. The framework covers a broad range of capabilities, including modular route management

Micro is a minimalist Node.js web framework designed for creating lightweight, asynchronous HTTP services and JSON APIs. It serves as a low-footprint library for deploying asynchronous handlers focused on high request volumes and minimal overhead. The framework utilizes a functional request and response model, routing traffic to a single exported asynchronous function as the primary entry point. It specializes in processing incoming JSON requests and returning formatted responses with automated error handling. Core capabilities include request body parsing for JSON, plain text, and binary bu

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

This project is a technical study and analysis guide focused on the internal architecture of Node.js. It provides an in-depth examination of the runtime, focusing on how the engine manages memory handles, executes asynchronous operations, and implements core module logic. The guide specifically analyzes the integration of native C++ classes and functions into JavaScript and documents the behavior of the libuv event loop. It includes detailed references for optimizing performance by identifying V8 compiler bailouts and profiling execution to improve resource efficiency. The material covers a

Swift NIO is a low-level, event-driven network framework for the Swift language. It serves as an asynchronous network protocol stack and I/O library designed to build high-performance network servers and clients that handle thousands of simultaneous connections. The framework functions as a high-concurrency network engine that dispatches events across multiple CPU cores. It enables the implementation of custom network protocols by processing raw bytes through a sequence of reusable data transformation handlers. The system provides capabilities for non-blocking I/O multiplexing, asynchronous

CocoaAsyncSocket is a networking library for macOS and iOS that provides core components for managing asynchronous TCP and UDP streams. It implements non-blocking network communication to maintain application responsiveness during data transfers, featuring a delegate-based system for managing connection streams and packet handling. The library includes a secure communication layer that wraps TCP sockets to apply encryption standards, protecting client and server traffic from unauthorized interception. Its capabilities cover non-blocking connection management for both stream-based TCP and pac

Nonebot2 is an asynchronous Python framework for building event-driven chatbots across multiple messaging platforms. It centers on a non-blocking event bus and a driver-based adapter system that unifies different messaging protocols into a single consistent interface. The framework utilizes a modular plugin architecture, allowing for the discovery and loading of third-party extensions to add new event handlers and system capabilities. It distinguishes itself with a type-annotation based dependency injection system that automatically resolves and provides required service objects to handlers a

Mosn is a multi-protocol network proxy designed for cloud-native service meshes, API gateway management, and distributed load balancing. It forwards layer four and layer seven traffic across diverse network protocols to ensure interoperability between distributed cloud components. The project is distinguished by its ability to perform zero-downtime proxy updates, replacing the running binary while maintaining existing network connections. It further supports dynamic proxy extension, allowing custom request processing logic to be added via external plugins or compiled Go modules without restar

Quart is an asynchronous Python web framework that implements the ASGI specification. It is used to build high-performance HTTP and WebSocket services, JSON REST APIs, and web applications using async and await syntax for non-blocking request handling. The framework supports persistent bidirectional communication via WebSocket API servers and enables the proactive delivery of assets through HTTP server push. It also includes a template engine for rendering dynamic HTML web pages and supports incremental request and response streaming to manage large payloads. General capabilities cover reque

Boost is a collection of portable, high-performance source libraries that extend the C++ standard library. It provides a wide range of reusable components, data structures, and algorithms designed to add capabilities to the base language across different platforms. The project is distinguished by its extensive focus on compile-time template metaprogramming and generic programming. It implements advanced architectural patterns such as policy-based design, concept-based type validation, and the use of SFINAE for conditional template resolution to minimize runtime overhead. The library covers a

Skill-Tree is an educational framework designed to map theoretical technical concepts to practical implementation pipelines and structured interview preparation. It organizes technical knowledge into a tree-based index to enable structured navigation and uses a theory-to-implementation pipeline to verify conceptual understanding through concrete software tasks. The project provides curated study paths and cross-referenced indexing that links common interview questions and simulated exam sets to specific technical modules. It employs module-based subject isolation to separate diverse backend d

VidGear is a high-performance Python video processing framework designed for capturing, transcoding, and manipulating video streams. It functions as a multi-protocol video streamer and a WebRTC streaming server, enabling the transfer of video frames over networks using RTSP, RTMP, RTP, and MJPEG protocols. The project distinguishes itself through hardware-accelerated video transcoding and decoding using GPU backends like CUDA to reduce CPU load. It includes a cross-platform screen capture tool and a specialized system for establishing direct peer-to-peer media connections using WebRTC signali

Curio is a Python library for structured concurrency and asynchronous network programming. It serves as a framework for handling thousands of simultaneous TCP connections using non-blocking sockets and high-throughput I/O. The library organizes asynchronous operations into a hierarchy of parent and child coroutines to ensure reliable termination and cleanup of dependent tasks. It provides a toolkit for coordinating these concurrent operations through the use of task groups and timeouts. The framework covers a broad range of concurrency management capabilities, including inter-task communicat

Practicalnode is a comprehensive educational resource and backend development framework for mastering server-side programming with Node.js. It provides a structured approach to building scalable network services, REST APIs, and real-time applications using asynchronous JavaScript. The project serves as a detailed implementation guide for several core backend patterns, including MongoDB data modeling and the construction of REST API development kits. It emphasizes a specific workflow for Docker containerization and offers a variety of strategies for managing user identity through stateless tok

netty-socketio is a Java implementation of a Socket.IO server designed for real-time bidirectional communication between clients and servers. It functions as a real-time event engine and WebSocket communication server, utilizing the Netty network framework to manage high-performance socket connections. The project enables distributed socket server scaling by acting as a distributed message broker. It synchronizes client states and broadcasts messages across multiple server nodes through the use of an external data store. The system manages traffic via namespace-based connection routing and r

This is a non-blocking network client for Java applications that provides asynchronous HTTP request capabilities and bidirectional WebSocket connectivity. It leverages a Netty-based architecture to handle high volumes of network input and output. The library utilizes native transport abstractions such as Epoll, KQueue, and io_uring to reduce system latency. It supports HTTP/2 multiplexing to run multiple concurrent request-response streams over a single connection and provides automatic response body decompression for various formats. Core capabilities cover the management of complex network