Abstract: “We survey the use of Abstract State Machines in the area of programming languages, namely to define behavioral properties of programs at source, intermediate and machine levels in a way that is amenable to mathematical and experimental analysis by practitioners, like correctness and completeness of compilers, etc. We illustrate how theorems about such properties can be integrated into a modular development of programming languages and programs, using as example a Java/JVM compilation correctness theorem about defining, interpreting, compiling, and executing Java/JVM code. We show how programming features (read: programming constructs) modularize not only the source programs, but also the program property statements and their proofs.”