Programming Scala by Dean Wampler and Alex Payne.
Experimental book at O’Reilly Labs.
Seems to be the day for not-strictly topic map posts but I think Scala is going to be important both for topic maps as well as scalable programming in general.
I suspect that reflects my personal view that functional approaches to merging are more likely to be successful with topic maps than approaches that rely upon mutable objects.
Comments about your experience with Scala, particularly with regard to topic maps and with this book most welcome!