Open-source alternatives to Plug

Warp is a Rust HTTP web framework designed for building high-performance web servers. It provides a system for managing request pipelines, implementing WebSocket servers for bidirectional communication, and serving static assets from the local filesystem. The framework is characterized by its use of type-safe request pipelines and routing. It utilizes a filter-based approach to extract and validate metadata from headers, query strings, and request bodies before they reach the application handler. Broad capability areas include HTTP API development, asynchronous task execution, and state-base

Hug is a Python API framework used for building web services by mapping functions to HTTP endpoints via decorators and type annotations. It functions as a type-based validator that automatically converts and validates incoming request data based on Python type hints and serves as a WSGI-compliant web framework for deployment on production servers. The project is distinguished by its ability to automatically generate API specifications and user-facing documentation derived from function signatures. It further extends the utility of internal logic by exposing functions as terminal commands thro

Echo is a high-performance, lightweight web framework for Go designed for building scalable RESTful APIs and web services. It provides a centralized environment for mapping network requests to handler functions, utilizing a fast radix-tree routing engine to ensure efficient request dispatching. The framework is built around a modular, middleware-centric pipeline that allows developers to execute reusable logic for cross-cutting concerns like authentication, logging, and security across the entire application. What distinguishes Echo is its focus on developer productivity through structured da

This project is a comprehensive library of reference implementations and patterns for building web applications using the Go Fiber framework. It provides curated templates and implementation guides for creating REST APIs, web servers, and structured backend services. The repository serves as a practical resource for applying architectural patterns, including Clean and Hexagonal architectures, as well as port-and-adapter decoupling. It offers detailed examples for integrating common web features such as OAuth2 authentication, JWT verification, WebSockets for real-time communication, and server

Polka is a minimalist Node.js web framework and HTTP routing engine. It provides a small-footprint server implementation designed for low overhead, mapping URL paths and HTTP methods to specific handler functions. The project utilizes a middleware-based architecture, processing requests through a sequence of functions to handle tasks such as logging, authorization, and data modification. It allows for the organization of these functions into global and path-filtered groups to control execution order. The framework covers core web capabilities including route parameter extraction, request URL

Grape is a RESTful web service framework for Ruby designed for building structured APIs. It provides a declarative syntax for routing and parameter validation, allowing developers to map HTTP verbs to logic through a domain specific language. The framework is distinguished by its built-in support for service versioning, which can be managed via URL paths, custom headers, or request parameters. It also features a modular architecture that allows large services to be constructed by nesting smaller API definitions. The project covers comprehensive API lifecycle capabilities, including schema-dr

Fiber is a high-performance web framework designed for building scalable HTTP services with minimal memory overhead. It provides a comprehensive runtime environment for managing the full request lifecycle, utilizing an optimized radix tree for high-speed route matching and an object pooling system to reduce garbage collection pressure during traffic processing. The framework distinguishes itself through its multi-process architecture, which supports prefork socket reuse to distribute incoming traffic across all available CPU cores. It offers a modular approach to application development, feat

This project is a request router and web framework for the Go programming language. It provides a toolkit for matching incoming HTTP network requests to specific handler functions by evaluating criteria such as URL paths, request methods, headers, and hostnames. The framework distinguishes itself through its flexible matching capabilities, which include support for regular expressions and dynamic variable extraction from URL segments. It allows developers to organize routes into logical hierarchies, share common path prefixes, and maintain a central registry of named routes to facilitate prog

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

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

Elysia is a high-performance TypeScript web framework designed for building type-safe backend services. It provides a modular, plugin-based architecture that allows developers to compose server logic, middleware, and validation schemas into scalable application instances. By leveraging native web standards, the framework ensures portability across diverse JavaScript runtimes, including Node.js, Deno, and various edge computing environments. The framework distinguishes itself through its focus on end-to-end type safety, automatically synchronizing request and response definitions between the s

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

Hono is a lightweight web framework built on Web Standard APIs that executes across JavaScript runtimes including Cloudflare Workers, Deno, Bun, and Node.js.

CodeIgniter is a PHP web framework built on the Model-View-Controller pattern, designed for building full-stack web applications. It provides a lightweight toolkit with minimal configuration, organizing application logic into controllers, models, and views for clean separation of concerns. The framework includes a fluent query builder for constructing SQL statements programmatically, PSR-4 autoloading with namespace mapping, and a service-based dependency injection container for managing shared class instances. The framework distinguishes itself through its comprehensive set of built-in tools

Connexion is a specification-driven framework for building APIs that automatically maps OpenAPI specifications to application logic. It uses these specifications to automate routing, request validation, and response serialization, linking API operations to backend handler functions via operation IDs. The project differentiates itself by providing a schema-driven mock server that simulates API behavior using example responses from the specification without requiring backend logic. It also includes a dynamic documentation hosting system that translates the API specification into a live interact

Cowboy is a high-performance HTTP server for Erlang and OTP. It is designed to handle web traffic with low memory usage and can be used as a standalone server or as an embedded networking library integrated directly into an existing application. The project implements modern transport protocols, including HTTP/3, QUIC, and WebTransport, to enable faster connections and bidirectional data streaming. It also functions as a real-time communication server supporting Server-Sent Events for pushing asynchronous updates to clients. Broad capabilities include path and content-type based request rout

Hono is a minimal JavaScript HTTP framework designed for building web servers across multiple runtimes, including Node.js, edge runtimes, and serverless platforms. It functions as a cross-runtime web server and a web standard API wrapper, normalizing various runtime request and response objects into standard Web API signatures. The project serves as an HTTP middleware orchestrator and request handler, utilizing a middleware-based request pipeline and hierarchical route mounting to create modular server structures. It distinguishes itself through a runtime-agnostic event wrapper that ensures c

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

Crow is a minimalist C++ micro web framework designed for building fast web servers and REST APIs. It provides a lightweight toolkit for web development in C++, offering core routing and request handling capabilities. The framework includes a built-in JSON parser for converting strings into structured data and an HTML template engine for generating dynamic web pages on the server. It also functions as a WebSocket server library to enable bidirectional, real-time communication between servers and web clients. Additional capabilities include a middleware-based request pipeline for executing sh

This project provides a comprehensive implementation of the WebSocket protocol, enabling persistent, bidirectional communication between clients and servers. It handles the low-level complexities of the protocol, including the initial HTTP upgrade handshake and the encapsulation of data into discrete binary frames. By managing these connections, it allows applications to exchange data instantly without the overhead associated with repeated standard request cycles. The library distinguishes itself through its focus on high-frequency message exchange and concurrent connection management. It uti

Chi is a lightweight, idiomatic router and middleware framework for building web services in Go. It is designed to integrate directly with the standard library, providing a set of utilities for managing HTTP request routing, context propagation, and modular service composition. The project distinguishes itself through a radix-tree-based routing system that supports recursive nesting, allowing developers to mount independent sub-routers onto specific path prefixes. This hierarchical structure enables the creation of organized, modular applications where request handlers are grouped and managed

Symfony is a full-stack web framework designed for building scalable and maintainable server-side applications. It provides a comprehensive collection of decoupled components that form a foundational architecture, centered on a robust dependency injection container and a configuration-driven routing engine. By organizing code into modular services, the framework ensures that application components remain testable and loosely coupled throughout the development lifecycle. The framework distinguishes itself through an event-driven kernel architecture that allows developers to intercept and modif

Revel is a full-stack web framework and toolkit for building applications with the Go language. It implements a model-view-controller architecture to separate business logic from user interface rendering, providing a comprehensive system for routing, parameter binding, and session management. The project distinguishes itself with a high-productivity development environment featuring automatic code compilation and hot-reloading, which refreshes the application state and templates upon file changes without requiring manual restarts. It also employs reflection-based parameter binding to automati

koa2-note is a project focused on Koa2 web server development and Node.js asynchronous programming. It provides a framework for building web servers and APIs using an asynchronous middleware pipeline to handle request and response cycles. The project emphasizes a layered backend architecture that decouples routing, business services, and data models. It distinguishes itself through the integration of relational databases for persisting user sessions and application data, alongside a build process that includes JSX-to-JavaScript compilation for frontend assets. The capability surface covers b

RoadRunner is a high-performance application server and process manager designed to serve PHP applications using a persistent worker model. It eliminates bootload overhead and initialization time by keeping application processes alive between requests, acting as a protocol-agnostic proxy that routes traffic to a pool of supervised workers. The server is built with a plugin-based modular architecture, allowing it to be extended with custom Go plugins and compiled into tailored binaries. It distinguishes itself by providing a unified execution model for a wide array of communication protocols,

Hyper is a low-level networking library designed for building high-performance HTTP clients and servers. It provides a foundational toolkit for creating network services that leverage asynchronous execution and memory-safe data handling, supporting both HTTP/1 and HTTP/2 protocols. The library distinguishes itself through a protocol-agnostic architecture that separates transport logic from HTTP semantics. It utilizes a service-trait abstraction to decouple network logic from the underlying transport, enabling developers to inject custom middleware for request interception and response transfo

NanoHTTPD is a lightweight, embeddable HTTP server for Java applications. It allows developers to integrate web server capabilities directly into a Java project to handle incoming requests without requiring a standalone installation. The project provides specialized implementations for an HTTPS web server, a WebSocket server for bidirectional real-time communication, and a static file web server. These capabilities enable secure network traffic through SSL certificates and the delivery of local files with automatic MIME type detection. The server includes systems for request routing and hand