Changing Java Programs

The promises of object-orientation and distributed computing could be delivered if the software we needed were written in stone. But it isn't, it changes. The challenge of distributed object-oriented maintenance is to find a means of evolving software, which already has a distributed client base. Working within this scenario, we observe how certain object-oriented language systems seek to support differing client requirements and service obligations. In particular, we examine how the Java Language Specification (JLS) facilitates the concept of binary compatibility, a useful property, but one that may introduce a class of clients who dare not re-compile! Following a suggestion in the new draft JLS, we describe our tool to manage distributed version control and we formulate some proposals for future developments.