gafter writes "An early access prototype implementation of the proposed new J2SE 1.5 language features is available. The prototype includes generics (JSR 14), typesafe enums, varargs, autoboxing, foreach loops, and static import (JSR 201). In other words, all the new language features planned for 1.5 except metadata (JSR 175). The prototype includes full sources for the compiler, written in the extended language. You can download the prototype from java.sun.com. It requires J2SE 1.4.1 and provides some examples of how to use the new language constructs. The prototype includes an experimental type system (variant type parameters) for Generic Java that is being considered for Tiger (1.5) based on a paper by Igarashi and Viroli at ECOOP 2002 . Comments and votes for the new type system are being gathered at bugParade."