Esper 9.0.0
Free
GNU GPL (GPL v2)
Checked 3 Oct 2026
Plans and prices
Esper pricing
Esper Open Source
Free
GPLv2 license · Java/JVM and .NET/NEsper · software supplied as-is
Checked 15 Oct 2026
Esper Enterprise Edition
Priced on request
closed-source commercial product · horizontal scaling · REST services · GUI · JDBC/JMX · commercial support
Checked 15 Oct 2026
EsperHA
Priced on request
high-availability add-on · state resilience · fast recovery · enterprise support
Checked 15 Oct 2026
Esper support
Priced on request
Production support: Bronze, Silver, Gold · Development support: Developer Seat
Checked 3 Oct 2026