1) Are EAI , SOA and ESB some sort of concepts or software frameworks ?
In my opinion Enterprise Application Integration (EAI) is the notion of service-oriented, information-oriented, process-oriented. The notion of EAI is really a complete stack, encompassing all types of integration patterns. It's really a concept rather than a software framework. I defined EAI as encompasses approaches, methodologies, standards, and technologies allowing very diverse but important systems to share information, processes and behavior in support of the core business. Service Oriented Architecture (SOA) has become a well established concept in the field of Information Technology. SOA is a business concept used for designing business services with an emphasis on cost efficiency, maintenance and ability to create new business models and products. SOA also brings cost effective, reusable and low lead time solutions to an organization but EAI and SOA are both going to coexist. Enterprise Service Bus (ESB) is a more technical concept that is related to implementing a specific section of a Service Oriented Architecture (SOA). It would only be a small part of a much bigger architecture. I defined the concept of ESBs in the EAI as what it is an enabling technology for EAI. EAI is a larger notion, where ESBs are a mere instance of technology. It's almost like saying Automobiles are better than the concept of transportation.
Neither one of these is a software framework. SOA is a business methodology and ESB is a technical tool used to implement a specific element of a specific SOA implementation
2) What are the commercial/open source products available,implementing these concepts?
Service-oriented architecture (SOA) are very complex and have many different levels and can be viewed from multiple perspectives. There are many products which can be used to implement various "technical" parts of a SOA. One example is the open source SOA. Open source...