Open-source alternatives to Arduino Mqtt

This project is a Java messaging software development kit designed to facilitate real-time data exchange between applications and message brokers. It functions as an MQTT client library, providing the necessary tools to implement publish-and-subscribe messaging patterns within distributed systems and internet-connected device environments. The library distinguishes itself through its focus on resilient network connectivity and reliable message delivery. It manages persistent connections through internal state machines that handle automatic reconnection and keep-alive heartbeats, ensuring stab

libwebsockets is an event-driven networking framework written in C. It provides a suite of tools for implementing HTTP servers and clients, WebSocket bidirectional communication, MQTT client messaging, and TLS-enabled socket encryption. The project distinguishes itself through a non-blocking event-loop architecture capable of scaling to high connection volumes by distributing network sessions across multiple service threads. It uses a protocol-based callback system and a pluggable event loop integration that allows the networking core to synchronize with external system event libraries. The

Mosquitto is an MQTT message broker and IoT messaging server designed to route data between publishers and subscribers. It functions as a centralized network hub that enables lightweight communication between distributed sensors, controllers, and other internet-of-things devices. The project includes an MQTT bridging gateway used to link separate brokers, allowing traffic to be routed and synchronized across different network locations or security zones. It also provides a client implementation for connecting to and interacting with the broker. The system manages topic-based message routing

MQTTnet is a comprehensive MQTT library for .NET that supports both client and broker roles in a single codebase. It provides a full-featured broker implementation capable of hosting a server with access control, message interception, session persistence, and support for mixed MQTT protocol versions. The client side offers robust publish-subscribe communication with automatic reconnection that preserves quality-of-service guarantees, ensuring reliable message delivery across network interruptions. The library distinguishes itself with a plugin-based authentication pipeline for validating clie

MQTTX is a cross-platform MQTT client application designed for testing, debugging, and managing MQTT brokers. It supports both MQTT v3.1.1 and v5.0, enables simultaneous management of multiple broker connections, and provides an interactive chat-style interface for publishing and subscribing with configurable quality of service, payload transformation, and topic visualization. The client can be used as a desktop application, a command-line tool, or a self-hosted web client deployable via Docker. What sets MQTTX apart is its integration of AI-assisted workflows, allowing users to generate MQTT

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

open62541 is an open-source implementation of the OPC Unified Architecture standard, providing a complete stack for industrial automation and data exchange. It functions as both an OPC UA server and client, enabling the creation of an object-oriented address space to model physical industrial assets and their relationships. The project is designed for versatility across diverse hardware, offering a C99 library that can be deployed to both cloud servers and resource-constrained embedded environments. It distinguishes itself through a pluggable network layer and interface-based security backend

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

NATS Server is a high-performance, lightweight messaging system designed for cloud-native applications, edge computing, and distributed microservices. It functions as a distributed publish-subscribe broker that routes messages using hierarchical, dot-separated subject strings, enabling decoupled communication between services without requiring centralized broker lookups. The system supports core messaging patterns including asynchronous publish-subscribe, request-reply, and load-balanced queue processing. The platform distinguishes itself through a decentralized architecture that eliminates t

FastStream is an asyncio message broker framework for building event-driven applications in Python. It provides a unified interface and a multi-broker messaging abstraction layer that translates generic producer and consumer calls into broker-specific APIs. The framework features a built-in dependency injection container and uses decorators to route messages to asynchronous handler functions. It includes a documentation generator that extracts channel definitions and message formats from code to produce standardized AsyncAPI specifications. The project supports integration with Kafka, Rabbit

This is a Python WebSocket client library designed to establish full-duplex, persistent network connections for real-time exchange of text and binary data. It functions as an asynchronous network client and a TCP socket wrapper, managing the complete lifecycle of a connection from the initial handshake to graceful closure. The implementation includes a secure WebSocket client that handles SSL/TLS encryption, certificate verification, and secure handshake protocols. It further distinguishes itself by supporting advanced connectivity options, including proxy routing via HTTP or SOCKS proxies an

MQTTnet is a .NET library providing a framework for implementing MQTT clients and brokers. It includes a broker implementation for hosting a central message hub that routes messages between connected clients and a client library for publishing and subscribing to messages. The project supports both TCP and WebSocket transport layers, enabling secure data traffic through transport layer security. It allows for the development of custom middleware to intercept, transform, or validate messages as they pass through a server. Capability areas include distributed message routing, persistent connect

WebSocket-Node is a server-side implementation of the WebSocket protocol for Node.js environments. It serves as a framework for establishing persistent, bidirectional communication channels and low-latency data exchange between clients and servers. The project provides a secure socket implementation using transport layer security and includes an integrated client for establishing outbound encrypted connections. It utilizes a formal protocol-state machine and an event-driven connection framework to manage high-concurrency network streams. The framework covers server-side infrastructure includ

This project is flight control autopilot software designed as a real-time operating system for managing the flight dynamics and navigation of autonomous multicopters, fixed-wing aircraft, and rovers. It serves as a multi-vehicle autopilot framework that supports various aircraft configurations, including vertical takeoff and landing platforms across industrial environments. The system includes a MAVLink communication stack for exchanging telemetry and command data between unmanned vehicles and ground control stations. It also provides a software-in-the-loop flight simulator to test autopilot

XMPPFramework is an Objective-C communication framework and networking library used to build instant messaging applications for Mac and iOS. It provides a programmatic foundation for implementing XMPP clients, managing real-time message exchange, and processing structured XML streams between network endpoints. The framework features a modular plugin architecture and extension system that allows for the integration of custom communication capabilities and protocol extensions into the data stream. It distinguishes itself with specialized support for OMEMO end-to-end encryption and a state-based

Olric is a distributed data grid and in-memory key-value store that partitions and replicates data across a cluster of servers. It serves as a shared memory system for managing distributed maps, performing atomic operations, and acting as an in-memory data cache. The system provides a distributed locking mechanism for concurrency control and a pub-sub messaging system that broadcasts and routes messages over named channels across the cluster. The platform covers wide-ranging capabilities including cluster management and orchestration, data replication with configurable quorums, and automated

freecache is a high-performance, concurrent in-memory key-value store library for Go applications. It functions as a fixed-size cache that manages large volumes of data while eliminating garbage collection overhead through the use of preallocated memory and off-heap storage. The system maintains a predictable memory footprint by utilizing fixed memory allocation and circular buffer management, where new entries automatically overwrite the oldest data upon reaching capacity. It further reduces contention between simultaneous readers and writers through lock-striped concurrent access. The libr

websockets is a Python library for building WebSocket servers and clients using coroutines and the asyncio framework. It provides a complete toolkit for creating production-ready WebSocket applications, including a coroutine-based framework for handling connections, messages, and lifecycle events, as well as a client library for opening persistent bidirectional connections to remote endpoints. The library manages the full lifecycle of WebSocket connections, including handshake, message exchange, and graceful closure, with support for path-based routing to organize server logic across multiple

BitChat Android is a decentralized peer-to-peer messenger that enables communication over Bluetooth mesh networks without requiring any internet connection or central servers. It functions as a full mesh network chat app and a privacy-focused communication tool, with every message encrypted end-to-end using per-session cryptographic keys that ensure forward secrecy. The app operates without accounts or persistent identifiers, resisting user tracking at the protocol level. To strengthen privacy and efficiency, BitChat injects cover traffic to obscure real communication patterns and includes an

This project is the official documentation site and communication standard portal for the MQTT messaging protocol. It serves as a central hub for technical specifications and implementation guidelines designed for lightweight messaging in internet-of-things environments. The site is implemented as a static website, utilizing static site generation and markdown-based content authoring to distribute protocol specifications and technical standards. The resources cover a broad range of industrial messaging and connectivity capabilities, including publish-subscribe routing, quality-of-service del

mQuickjs is a compact JavaScript engine designed for memory-constrained devices, such as microcontrollers, requiring as little as 10 KB of RAM and 100 KB of ROM. It achieves this through a fixed-buffer memory allocation scheme that avoids system heap usage, a compacting tracing garbage collector that eliminates fragmentation, and a ROM-embedded standard library that reduces both memory footprint and startup time. The engine compiles JavaScript source into portable bytecode that can be stored in persistent memory and executed without reparsing, and it emulates IEEE 754 floating-point arithmetic

RethinkDB is a distributed, document-oriented database designed to store and manage JSON-formatted data across scalable clusters. It utilizes a custom log-structured storage engine with B-Tree indexing to ensure high-performance disk I/O and data persistence. The system maintains high availability through automatic sharding and replication, employing a primary-replica voting consensus mechanism to handle node failures and ensure consistent cluster operations. A defining characteristic of the platform is its reactive changefeed engine, which allows applications to subscribe to live data update

rustls is a memory-safe implementation of the Transport Layer Security protocol written in Rust. It provides a cryptographic stack for secure network communication, supporting both TLS 1.3 and 1.2 standards for client and server implementations. The project is designed as a modular cryptographic library that allows swapping underlying cryptographic backends and primitive providers to meet specific security or performance requirements. It incorporates a post-quantum cryptography stack, utilizing hybrid key exchanges and signatures to protect data against future quantum computing threats. The

rustls is a modern implementation of the Transport Layer Security protocol written in the Rust programming language. It serves as a cryptographic transport layer for establishing encrypted connections between clients and servers to ensure data privacy and integrity. The library features a pluggable crypto provider framework, allowing the substitution of cryptographic primitive implementations to meet specific platform architecture or regulatory compliance requirements. It provides capabilities for secure server configuration to handle encrypted incoming connections and secure client connecti

FastStream is an asynchronous Python framework designed for building event-driven microservices. It provides a unified abstraction layer for interacting with various message brokers, enabling developers to manage event production and consumption through a consistent interface while maintaining access to native provider-specific features. The framework centers on a decorator-based routing model that binds application logic directly to broker topics, supported by a built-in dependency injection container that resolves resources at runtime. The framework distinguishes itself through its deep int

Redigo is a Redis client library for Go applications, providing the means to execute commands, manage connections, and interact with Redis data stores. The library includes a connection pool manager to maintain a cache of reusable open connections and a pipelining tool that groups multiple commands into a single network round-trip to increase throughput and reduce latency. It also provides an implementation for broadcasting events and receiving real-time messages through Redis communication channels. The project covers broader capability areas including remote scripting for executing logic o

Mongoose is an embedded networking library providing TCP/IP stacks, web server hosting, and IoT device connectivity. It enables microcontrollers and desktop systems to implement network protocols including HTTP, WebSocket, and MQTT. The project provides a bare-metal TCP/IP stack for environments without a native operating system and includes built-in TLS and ECC encryption to secure network traffic. It features a binary-embedded file system to serve web content directly from the executable and supports over-the-air firmware updates for managing device fleets. Additional capabilities cover as