Oracle Service Bus is a proven, lightweight and scalable SOA integration platform that delivers low-cost, standards-based integration for high-volume, mission critical SOA environments. It is designed to connect, mediate, and manage interactions between heterogeneous services, legacy applications, packaged applications and multiple enterprise service bus (ESB) instances across an enterprise-wide service network. Oracle Service Bus is a core component in the Oracle SOA Suite as a backbone for SOA messaging. Source: http://www.oracle.com/technologies/soa/service-bus.html
With the acquisition of BEA, the AquaLogic Service Bus (ALSB) joined the Oracle family as well. ALSB was renamed to Oracle Service Bus (OSB) post acquisition. On July 1, 2008, Thomas Kurian, the Senior Vice President of Fusion Middleware, announced the strategic roadmap for Oracle middleware and BEA products. He announced that OSB would be the strategic service bus going forward, with its wide customer adoption, and advanced product capabilities.