Gun vs ably: What are the differences?

Introduction:
Gun and Ably are both real-time data synchronization platforms that provide tools and services for developers to build applications that require real-time updates and communication.

1. **Communication Protocol**: One key difference between Gun and Ably is the communication protocol they use. Gun utilizes a peer-to-peer protocol, allowing direct communication between nodes without the need for a centralized server. In contrast, Ably uses a pub/sub model where messages are routed through Ably's server infrastructure.

2. **Data Storage**: Another significant difference is in how data is stored and synchronized. Gun stores data in a decentralized manner across all connected nodes, enabling data to be persisted even if some nodes go offline. On the other hand, Ably's data is stored centrally in its server infrastructure, providing a single source of truth for all connected clients.

3. **Scalability**: When it comes to scalability, Gun's decentralized approach allows for horizontal scaling as more nodes can be added to the network to handle increased traffic. Ably, with its centralized architecture, provides vertical scaling where additional resources are added to a single server instance to handle more traffic.

4. **Authentication and Authorization**: Gun does not have built-in authentication and authorization mechanisms, as it relies on the security of the underlying network protocol. In contrast, Ably offers robust authentication and authorization features, allowing developers to control access to channels and data based on specific permissions and roles.

5. **Real-time Presence**: Ably provides real-time presence functionality, which allows developers to track the online status of users in real-time. This feature is not natively supported in Gun, requiring developers to implement custom solutions for real-time presence tracking.

6. **Offline Support**: Gun offers robust offline support, allowing data to be synchronized between nodes even when they are offline. Ably provides limited offline support through its message queuing feature, but it does not offer the same level of offline capabilities as Gun.

In Summary, Gun and Ably differ in their communication protocols, data storage mechanisms, scalability options, authentication features, real-time presence functionality, and offline support capabilities.