SystemReactive

SystemReactive is an open-source framework for building reactive, event-driven software systems. It provides a runtime and libraries to model data streams, asynchronous computation, and fault-tolerant coordination, prioritizing backpressure, composability, and observability.

The programming model is based on streams and operators. Applications are constructed as graphs of streams flowing through combinators such as map, filter, merge, groupBy, window, and join. The runtime enforces backpressure, provides asynchronous boundaries, and supports stateful operators with snapshotting and recovery. Connectors enable integration with message queues, databases, timers, HTTP services, and other I/O.

Architecture consists of a core runtime, a streaming library, and a collection of adapters. It supports deployment from a single process to clustered environments, with fault isolation and configurable restart strategies. State can be stored in pluggable stores, and events can be delivered using exactly-once or at-least-once semantics depending on configuration and store support.

History and usage: SystemReactive originated in the early 2010s as a research concept and matured into an extensible platform with multiple releases. It has been applied in cloud-native microservices, IoT, and real-time analytics domains, with emphasis on interoperability with other reactive ecosystems and strong observability through tracing, metrics, and logging.