Esper

Detects complex patterns and sequences across event streams in real-time, as highlighted in the README for fraud detection and IoT monitoring.

Offers a SQL-like query language for continuous queries, enabling familiar syntax for filtering, aggregation, and joins on streaming data.

Available as Esper for Java and NEsper for .NET, catering to diverse runtime environments without vendor lock-in, per the project description.

Processes high-volume event streams with immediate response, critical for time-sensitive applications like financial trading or alerting systems.