I think that you will find R appropriate for web mining and and web applications. In my own work, I use R as an exploratory data mining tool and do not build adaptive systems, but there are certainly many examples available.
Mark Lui wrote:Oriol,
Source code is available at the Apress website:
It's just an API with libraries that implement support for connecting to, and sending and receiving events from, external systems.
I would definitely recommend Spring Integration for learning enterprise integration.