Messaging services offered by Tibco

Tibco is better known to the world for its messaging solutions. In all there are three products in Tibco stable which deals with the core messaging as such. The most popular being the Tibco Rendezvous (Inside Tibco known it is known as RV) complimented by Tibco's own JMS implementation in the form of EMS(Enterprise messaging service) and the latest offering in the form of AMS(Ajax Messaging service) (yours truly being fortunate enough to have worked on its development). The thing that is common to all being the word message.

Now one of the first questions that will come into reader's mind is why do we need so many messaging solutions. I will deal this question by clearing the doubt about the utilities of EMS and RV first ( later i will come to AMS).
Rv is based on multicast publish/subscribe model whereas EMS is based on hub and spoke model. This means that the publisher will broadcast a single copy to the listeners and the deamon(rvd running on each host) will be responsible to collect the data from the information bus. Only if someone (subscriber) reports a non acknowledgement (NAK) then only the publisher will resend the data. Thus increasing efficiency of the system by a considerable amount. EMS's hub and spoke model will send a copy to each recipient. One would say that why would one not use Rv for each system then which seems to be more efficient. The answer could be many and will be clear in the following articles. Now what purpose does AMS serves. AMS has a server known as lightstreamer in its core which continually updates the data (Streaming will be a better word). AMS adapts the messaging paradigm provided by RV and EMS to connect it with internet to distribute these messages in real time to the user's browser with the help of technology known as Reverse AJAX(or PUSH technology). In this way AMS compliments what RV and EMS does.