JPF: From 2003 to 2023.

AbstractWe give an account of JPF’s current architecture as it has evolved over the last 20 years. Key changes include a modular, extensible design, and Java 11 support.Java 11 brought with it fundamental changes in the language and its runtime, in particular, a new modular library system, different compilation of string expressions to bootstrap methods, and changes in many internal interfaces that allow access to the loaded code and the virtual machine state. These changes required numerous adaptations in JPF to ensure a successful compilation and correct behavior under Java 11.