So as typically is the case when a few positive posts arise about Groovy, an alternative view point has cropped up entitled "BeanShell: groovier than Groovy" by Ed Burnette. The article quotes only the last paragraph of my previous post about how Groovy is approaching its "second" version 1.0, conveniently brushing over and failing to comment on any of the benefits highlighted.
Unfortunately, this is where many Java developers, with all due respect to Mr Burnette, fail to understand what a "dynamic" language is and its a shame this misunderstanding is being spread. I like BeanShell I appreciate what they are trying to do and in certain circumstances would recommend it over Groovy. It is great for embedding in Java applications if you want to script say an application server or or server component, but the fundamental difference is that BeanShell is a scripting language for the Java language, whilst Groovy is a "dynamic" language for the JVM (note the difference between Java the language and the JVM).
BeanShell is essentially Java without the need to specify types, which is great in certain circumstances, but doesn't really have much productivity gain and is not in my opinion the answer to the JVMs dynamic needs. I have written a lot of code in both BeanShell and Groovy and with Groovy my lines of code (LOC) count is about 60-70% less then the equivalent Java code, with BeanShell this is about 10%, as its essentially just Java without the need for type safety.
This is also why BeanShell has managed to achieve relative stability and a small size (as highlighted in Ed's article) when compared to Groovy as its goals are relatively simple. Groovy adds new language constructs, closures, the GDK methods, builders, meta-programming etc. This is not something you can achieve without spending a longer period of time defining the language and the API. Yes, following the standardisation process there was a re-think of many of the aspects, but this is the usual process with the JSR and any standard spec. Fortunately the syntax, through this process, has been nailed down and the Groovy development team are merely focusing on improving the core of Groovy.