Pros of Emitter

• More feature-rich, including support for presence, security, and clustering
• Better documentation and community support
• Actively maintained with regular updates

Cons of Emitter

• More complex setup and configuration
• Higher resource usage due to additional features
• Steeper learning curve for beginners

Code Comparison

Emitter (Go):

broker := broker.New()
broker.Listen(":8080")

HMQ (Go):

hmq := hmq.NewHmq()
hmq.Start()

Key Differences

• Emitter offers a more comprehensive MQTT solution with additional features like presence detection and security options
• HMQ focuses on simplicity and lightweight implementation
• Emitter has better documentation and community support, making it easier for developers to get started and troubleshoot issues
• HMQ may be more suitable for simple MQTT broker needs or resource-constrained environments
• Emitter provides better scalability options with built-in clustering support

Use Cases

• Choose Emitter for complex, feature-rich MQTT applications requiring advanced security and scalability
• Opt for HMQ when a lightweight, simple MQTT broker is needed, especially in resource-limited environments

Both projects are open-source and implemented in Go, making them suitable for cross-platform deployment and integration into existing Go-based systems.

Pros of Mosquitto

• More mature and widely adopted project with extensive documentation
• Supports a broader range of MQTT features and versions
• Cross-platform compatibility (Windows, Linux, macOS)

Cons of Mosquitto

• Written in C, which may be less accessible for some developers
• Can be more resource-intensive compared to lightweight alternatives

Code Comparison

Mosquitto (C):

int mosquitto_publish(struct mosquitto *mosq, int *mid, const char *topic, int payloadlen, const void *payload, int qos, bool retain)

HMQ (Go):

func (c *client) PublishMessage(msg *message.PublishMessage) error

Key Differences

• Mosquitto is written in C, while HMQ is written in Go
• Mosquitto offers more comprehensive MQTT support
• HMQ focuses on high performance and scalability
• Mosquitto has a larger community and ecosystem
• HMQ provides built-in clustering capabilities

Use Cases

Mosquitto:

• Enterprise-grade MQTT deployments
• IoT projects requiring full MQTT specification support
• Cross-platform applications

HMQ:

• High-performance MQTT broker requirements
• Go-based projects seeking easy integration
• Scenarios where clustering is a priority

Both projects offer MQTT broker functionality, but Mosquitto is more established and feature-rich, while HMQ emphasizes performance and Go ecosystem compatibility.

Pros of VerneMQ

• More mature and feature-rich MQTT broker with extensive documentation
• Supports clustering for high availability and scalability
• Offers plugin system for extensibility and customization

Cons of VerneMQ

• Written in Erlang, which may have a steeper learning curve for some developers
• Larger codebase and potentially higher resource usage
• More complex setup and configuration compared to HMQ

Code Comparison

VerneMQ (Erlang):

handle_publish(Topic, Payload, _Opts, State) ->
    io:format("Received message on topic ~p: ~p~n", [Topic, Payload]),
    {ok, State}.

HMQ (Go):

func (c *client) ProcessPublish(msg *message.PublishMessage) {
    fmt.Printf("Received message on topic %s: %s\n", msg.Topic(), msg.Payload())
}

Both repositories implement MQTT brokers, but VerneMQ offers a more comprehensive solution with advanced features and scalability options. HMQ, being written in Go, may be easier for some developers to understand and modify. VerneMQ is better suited for large-scale deployments, while HMQ could be a good choice for simpler use cases or when Go expertise is available.

Pros of HiveMQ Community Edition

• More comprehensive documentation and community support
• Offers clustering capabilities for scalability
• Provides a web-based dashboard for monitoring and management

Cons of HiveMQ Community Edition

• Larger resource footprint due to its Java-based implementation
• More complex setup and configuration process
• Limited customization options compared to HMQ

Code Comparison

HMQ (Go):

func (c *client) ProcessPublish(packet *packets.PublishPacket) {
    topic := packet.TopicName
    payload := packet.Payload
    // Process publish message
}

HiveMQ Community Edition (Java):

@Override
public void onPublish(PUBLISH publish) {
    String topic = publish.getTopic();
    byte[] payload = publish.getPayload();
    // Process publish message
}

Both implementations handle MQTT publish messages, but HMQ uses Go's lightweight approach, while HiveMQ Community Edition leverages Java's object-oriented structure. HMQ's code is more concise, potentially offering better performance for high-throughput scenarios. However, HiveMQ Community Edition's approach may provide better maintainability and extensibility for complex use cases.

Pros of EMQX

• More feature-rich and scalable, supporting millions of concurrent MQTT connections
• Extensive documentation and enterprise support options
• Active development with frequent updates and a larger community

Cons of EMQX

• More complex setup and configuration compared to HMQ
• Higher resource requirements due to its comprehensive feature set
• Steeper learning curve for beginners

Code Comparison

HMQ (Go):

func (c *client) ProcessPublish(msg *message.PublishMessage) {
    topic := string(msg.Topic())
    r := c.srv.sl.Match(topic)
    // ... (implementation details)
}

EMQX (Erlang):

handle_publish(Packet, State) ->
    Topic = emqx_message:topic(Packet),
    Subscribers = emqx_router:match_routes(Topic),
    % ... (implementation details)

Both implementations handle MQTT publish messages, but EMQX's codebase is more extensive and modular, reflecting its broader feature set and scalability focus. HMQ's code is more straightforward, aligning with its lightweight design philosophy.

Pros of Moquette

• Written in Java, offering better integration with Java-based systems
• More extensive documentation and community support
• Supports WebSocket connections out of the box

Cons of Moquette

• Generally slower performance compared to HMQ
• Higher memory usage, especially for large-scale deployments
• Less frequent updates and maintenance

Code Comparison

Moquette (Java):

Server server = new Server();
Properties config = new Properties();
config.setProperty(BrokerConstants.PORT_PROPERTY_NAME, "1883");
server.startServer(config);

HMQ (Go):

hmq := broker.NewHmq()
hmq.Start()

Both projects aim to provide MQTT broker functionality, but HMQ focuses on high performance and low resource usage, while Moquette offers better Java ecosystem integration and more extensive features. HMQ's codebase is more concise and efficient, reflecting its Go implementation, while Moquette's Java code is more verbose but potentially more familiar to Java developers.