Some links that came to my attention recently on the subject of Functional/Hybrid languages and the "rise" of the JVM.
Firstly - Thoughtworks have a yearly "Radar" paper they publish which is based on their observations on the Enterprise usage of programming languages and databases:
"According to ThoughtWorks, in Languages & Frameworks the industry is undergoing a "seismic shift in programming languages" with functional hybrids, including Clojure and Scala, identified in the Adopt circle for the first time."
"Adopt circle" means they recommend their clients take it on as a "safe" choice - they are increasingly recommending JVM based FP hybrid languages - and also seeing update by clients (they were very bullish a few years ago for Ruby - but have since shifted to this direction it would seem)
Secondly - there are various articles over the year about Twitters shift to the JVM. The recent presidential election brought record usage to Twitter and it held up to the load - some people are attributing it to their recently years shift in direction to hybrid-FP and the JVM
Also, a talk from OSCON about twitter's shift in infrastructure:
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