August 9, 2013
Immutability, immutability, immutability.
Scheme, a little Clojure.
Relational- largely because I have several viable, production-ready vendors to choose from and I can be assured that every developer on my team will immediately grok any SQL-based implementation.
I have more or less built a career upon the JVM, making use of Java, Groovy, and a little Scala.