Esper

7.2easy start · #11 of 24
in Stream Processing Software

Free to practise onyes
Free trialnot on record
Well documentedyes
Runs where you worknot on record

Runs on api, Linux, self-hosted, Windows.

Esper is ranked #11 of 24 in stream processing software on The Geeks Club. It runs on API, Linux, Self-hosted, Windows. There is a free plan.

Esper plans and pricing

All plans

Esper 9.0.0 Free GNU GPL (GPL v2) espertech.com · 3 Oct 2026

Esper support Not published per year and per instance or per seat Production support: Bronze, Silver, Gold · Development support: Developer Seat espertech.com · 3 Oct 2026

Compared on stream processing software

Free plan: Yes
Deployment model: self-hosted
SQL processing: Yes
Stateful processing: Yes
Event-time windows: Yes
Supported languages: Java, C#

Best Esper alternatives

See all 12

Timeplus 0 of 4 in the starter kit Lesson 17.9 Confluent Cloud 0 of 4 in the starter kit Lesson 27.8 Materialize 0 of 4 in the starter kit Lesson 37.8 Feldera 0 of 4 in the starter kit Lesson 47.4 AFL++ 0 of 4 in the starter kit Lesson 57.3 Apache Storm 0 of 4 in the starter kit Lesson 67.3

The record

Purpose: Esper is a language, compiler and runtime for complex event processing and streaming analytics, available for Java and .NET.
Event language: Its Event Processing Language (EPL) implements and extends SQL for expressions over events and time.
Compilation: The Esper compiler compiles EPL into bytecode that can be packaged in JAR files for distribution and execution.
Runtime: The runtime is an in-memory streaming engine that the site describes as memory-efficient and low-latency, and says does not require external storage or services.
Scale: Esper’s runtime has a horizontal scale-out architecture with elastic scaling, load balancing, fault tolerance and multi-datacenter support, built on Apache Kafka and Apache Zookeeper in Esper Enterprise Edition.
Integrations: The feature list names CSV, JMS, HTTP, Kafka, database and socket input/output adapters, and JMX metrics exposure.
External data: Esper supports joining external data, including web services, relational databases through SQL-query joins and method invocation joins.
Licensing: The downloads page lists Esper 9.0.0 under GNU GPL (GPL v2), and EsperTech says it offers commercial redistribution licenses for companies incorporating Esper or NEsper.
Enterprise security: Esper Enterprise Edition says EsperHQ and EsperJMX can access CEP engines remotely over secured connections with user credentials.
Support: EsperTech offers production support with Bronze, Silver and Gold service levels, and a Developer Seat for development questions.
Support limitation: Developer Seat support answers how-to questions and does not fix software bugs or provide training.
Target use cases: The site lists business process monitoring, financial applications such as fraud detection, network and application monitoring, and sensor network applications as typical uses.
Current release: The documentation page identifies Esper and EsperIO 9.0.0 as the current release.
Founded: 2006
Price from: Free

Where it ranks on The Geeks Club

Best Stream Processing Software in 2026#11 of 24

Is Esper yours?

Claim it for free: prove the domain, then correct facts, plans and screenshots. An editor reviews every change.

Claim it free Promote Esper

Sources

espertech.com/esper/· checked 3 Oct 2026
espertech.com/esper/esper-downloads/· checked 3 Oct 2026
espertech.com/esper-enterprise-edition/· checked 3 Oct 2026
espertech.com/support/· checked 3 Oct 2026
espertech.com/esper/esper-documentation/· checked 3 Oct 2026