There are many who have contributed and shaped Java to make it as the most influential programming language of choice. Java software as a platform has grown leaps and bounds. There are more than 12 proprietary and 25+ opensource implementations of Java Virtural Machine. Not to forget the 100+ JVM languages including the high profile ones Clojure, Groovy, JRuby, Scala, AspectJ etc
Below the top 5 gurus or technologist (in my view) who have made the max impact on the growth of Java.
Note: Again, this is my take. I know everybody who works on Java has made an impact and will keep making an impact on the language :).
5. Kent Beck
@kentbeck , Blog
Kent Beck - creator of XP, TDD and JUnit. TDD in Java world is impossible without JUnit. Without TDD, there is simply no good code. All credit goes to Kent.
4. Joshua Bloch
The best book on Java till date is Effective Java ,written by Joshua. Its a must read for every Java programmer and arguably the best book. He also created Java collections framework and many features on the Java platform.
3. Rod Johnson
Creator of the Spring Framework, which has become the de-facto standard framework for creating enterprise Java applications. He ripped apart EJB pitfalls and made POJO development as the norm for enterprise class Java apps.
2. Rich Hickey
Creator of Clojure, a LISP dialect for the JVM. Clojure is extremely well received and adoption rate is impressive.
1. James Gosling
Father of Java language. It was year 1994 the year Java was born. Without James, there would have never seen Java.