Matt’s post on RIA Streaming Architectures is something we have experienced over the years too.
Liberator has always supported bidirectional messaging, but the first people to use it for trading still decided to do the trading part using an App Server, with real time responses and market data through Liberator – a kind of circular architecture. This wasn’t strictly down to the capabilities of Liberator, but more about using existing technology and skills rather than putting all eggs in the new tech basket.
In recent years we have focussed more on trading in the financial markets and customers have got more familiar with the technology, so they do it all through Liberator (Matt’s third generation). This allows the backend applications to work more like a real time event based application rather than being shoe horned into a web server paradigm.
We’ve built higher level APIs specific to the trading domain, rather than just the low level capabilities of request/response/topics/queues etc, so you don’t have to work out the best way to layer your domain model on top of a generic messaging system. This doesnt change the overall architecture as such, just how much of it you have to write yourself – so maybe it’s 3.5G 
