The lack of an effective modular programming model has frustrated Java developers since the Java platform's infancy. Until recently no single solution had stuck. In this article, Jeff Hanson explains why modularity is a next evolutionary step for the Java platform. He then surveys the two JSRs that propose to bring modularity to Java 7 -- JSR 291: Dynamic Component Support for Java SE and JSR 277: Java Module System. Both would bring the programming model popularized by OSGi to the Java platform, but they differ -- sometimes greatly -- in execution and philosophy.
