RJCE enables the editing of any method at runtime, applying the changes to any combination of objects, such as an array, or a complete class. It consists of a compiler, javaprec, and an IDE, Runtime Object Modifier (ROM). javaprec is used to compile programs, enabling runtime editing, and uses both sun.tools.javac and ANLTR for compilation. ROM is a JFrame used for editing methods, browsing classes, and viewing variables at runtime. It also includes an interpreter that runs Java scripts (which circumvent normal language access control) and is run from within any Java program. Aspects are also incorporated into RJCE, to enhance runtime editing.
