Many software vendors provide an enterprise service bus (ESB), one of the key pieces of infrastructure required for a service-oriented architecture (SOA). Now, the market is prepared for competition between commercial and open source license models. A unique combination of maturity, agility, and continuously evolving product requirements marks the ESB market. An open source offering that challenges the established vendors either has to race to add competitive features or try to succeed by driving mass adoption with lightweight capabilities. Recently spun off from Deutsche Post, open source ESB company SOPERA is a good example to study when exploring current product strategy options.