Spread

Spread is an exceptional open source toolkit for reliable and high-performance messaging services that is highly resilient to faults, traditionally found within local and wide area networks. As a unified message bus for distributed applications, spread offers highly tuned multicast, group communication, and point-to-point support, ranging from reliable messaging to fully ordered messages with guaranteed delivery. Spread can be deployed in many distributed applications that need high performance, high reliability, and robust communication among different subsets of members.

This toolkit is specifically designed to encapsulate the critical aspects of asynchronous networks, thus enabling the construction of reliable and scalable distributed applications. Spread is a composite of multiple components, including a library linked to user applications, a binary daemon running on every computer that is part of the processor group, and several other utility and demonstration programs.

Some of the critical features provided by Spread include:
- Scalable messaging and group communication
- Powerful and simple API for distributed architectures
- Simplicity in deploying and maintaining
- Highly scalable, from local area networks to complex wide area networks
- Supports thousands of groups with different sets of members
- Capability to enable message reliability despite machine failures, process crashes and recoveries, as well as network partitions and merges
- Provides a range of reliability, ordering, and stability guarantees for messages.
- Emphasis on robustness and high performance
- Completely distributed algorithms with no central point of failure.

The latest release of Spread (at the time of writing this review) has brought forth several improvements such as:
- Improved manageability by allowing dynamic configuration of sets of daemons without requiring a restart
- Improved performance
- Eased the development of Spread-based applications with better membership reporting
- Support for multi-threaded forking client applications
- Integration of a Virtual Synchrony interface
- Provision of simpler membership APIs
- More organized and improved software build for both Windows and UNIX systems.

In conclusion, Spread is a highly remarkable toolkit that provides a reliable and high-performance messaging service for highly distributed applications. If you seek to provide powerful and robust communication channels among several members, then Spread is a tool to add to your arsenal.