UltraESB is a lightweight enterprise service bus (ESB) capable of supporting many transports and message formats natively.

It allows messages to be mediated via Java or JSR 223 scripting languages through an API,[1] and is the first ESB to claim support for Zero-Copy proxying[2] of messages with Non-Blocking IO capabilities.

In 2013, it was selected as the ESB and API Management platform by a recent Fortune #1 company based on its performance and stability.

The initial version was published in January 2010 [3] and the code was subsequently open sourced under the OSI approved Affero General Public License (AGPL) in 24 August 2010.

[4] Continuous nightly builds[5] are there to ensure the performance of latest development code.