UltraESB is the first [and still the only] Open Source Enterprise Service Bus (ESB) to utilize Zero-copy proxying with Memory Mapped files and Java Non-Blocking IO for extreme performance!
ChainBuilder ESB is Java Business Integration (JBI) compliant open source solution for use in Service Oriented Architecture (SOA) environments. ChainBuilder ESB's graphical integration enables new and older applications to easily enter into SOA.
Project Open ESB implements an Enterprise Service Bus (ESB) runtime using Java Business Integration as the foundation. This allows easy integration of web services to create loosely coupled enterprise class composite applications.