Enterprise Service Bus (ESB) is an SOA-based software architecture for business application integration in distributed and heterogeneous environments. The proposed solutions so commercial as open source offer the same set of basic services such as message transformation, message routing, security. However, none of them take advantage of the multicore/multiprocessor technologies which make plausible the massively parallel processing. In this paper, we describe a new ESB architecture denoted Massively Parallel Application Bus (MPAB) which meets this challenge.