There are four main types of SOA products: Enterprise Service Bus, design-time governance, runtime management, and security gateway. The functionality of all four has always overlapped somewhat, though each still has certain unique characteristics not found in the others.
The most mature is ESB, which shuttles data between services. The least mature is governance, a combination of a catalog and a source code management system. Both are almost always provided as software. SOA management systems and security gateways are the equivalent of network management frameworks and firewalls, respectively, and can be provided as either hardware or software, sometimes from the same vendor.
The SOA Intermediary market is going through rapid consolidation as startups seek to expand beyond their niches and larger players offer suites that claim to cover all of a business' service integration needs. The consolidation is driven partly by the inherent overlapping functionality of traditional SOA intermediary products and partly by the extension of vendors from other market categories into the SOA arena.
