On Ola Bini's blog [1] you'll find this:

If you're building an application and chooses to use Groovy for this instead of Java, isn't the reason that you're doing that the fact that you expect Groovy to give you something Java does not? And if that's the case, doesn't it sound like a disservice to people picking up Groovy to say that they can begin by just programming Java. There is no gain here.

Ola thinks that beginning Groovy users hear "Groovy IS Java" when someone says "Groovy is like Java". Ola thinks they filter out the word like. If this is true then we should indeed be careful. But, ... I don't think beginning Groovy users do this.

When I say "Groovy is like Java [2]" I mean:

• Groovy compiles to Java byte-code
• A lot of Java statements work in Groovy too
• Groovy classes can be called from Java (including application or framework classes)
• Any existing Java class can be used in Groovy in at least the same ways as it can be used in Java
• Groovy classes can be debugged by the existing [3] debuggers [4] in Java IDEs, together with Java code (work in ongoing [5] to support this in NetBeans IDE too)
• Groovy and Java source code can be compiled together [6] so that Java classes and Groovy classes in the same code base can depend on each other
• Groovy is a dynamic language on the JVM that has tons of features to discover

New Groovy users are attracted because Groovy is like Java. It remains true enough to Java to be comfortable yet is different enough to be interesting. Groovy and Java form the perfect couple. You can combine Groovy and Java code in anyway way you want.

Why would Ola Bini think new Groovy users filter out the word like anyway?

Happy coding!