It seems funny that a chip manufacturer would be positioning a "soft appliance" over a hardware appliance but here they go:

The Intel SOA Expressway “soft appliance” design and feature emphasis is to improve the performance, scalability, security and manageability of SOA and other distributed systems architectures.  Although it is a SOA infrastructure software stack with orchestration, mediation, routing and integration capabilities, the design and feature emphasis is in different areas than many other implementations.  This has resulted in a different internal product architecture and focus on somewhat different usage models.  For example, in the area of architecture many ESB products rely on a specific implementation of messaging middleware to perform many of their functions where SOA Expressway can provide its feature set such as message acceleration, data integration, security, routing and manageability features on any JMS capable message bus (open source or vendor provided).   In the area of usage models, SOA Expressway operates as a very effective, high-speed perimeter security service providing high speed mediation functions like attachment encrypt / decrypt, sign / verify, LDAP integration, and policy enforcement.