Since you're already familiar with Java, consider using Clojure, a Lisp that runs on the JVM and therefore has access to all the Java libraries. Java and Clojur

Since you're already familiar with Java, consider using Clojure, a Lisp that runs on the JVM and therefore has access to all the Java libraries. Java and Clojure have full interactivity, so if you need speed, you can always move the performance-critical component to Java. Haskell has "state", but uses monads (design patterns derived from the type system) to segregate it carefully. Clojure has state, though "variables" are immutable by default and state requires the use of special concurrency-safe features.