A language extension to Java is introduced called XJ that allows DSLs to be constructed which are standard, portable and easily understood. The extension is conservative in the sense that it will not conflict with any existing language features and will preserve backward compatibility. The proposal extends classes with syntax definitions to produce new modular language constructs, called syntax-classes, that can easily be distributed along with an application in the usual way. The paper demonstrates XJ using a number of examples including demonstrating its application to Enterprise Java. The full proposal can be downloaded from: http://www.ceteva.com/book.html