Embodiments of the invention relate to hot-swapping a live dynamic code generator. In an embodiment, hot-swapping is done in the Java execution environment. The dynamic code generator to be hot-swapped is stored in a module of a shared library separated from other components of the Java environment such as the garbage collector, the class loader, the Java Native Interface, the threading and synchronization package, etc. A graphical user interface (GUI) is provided so that the user can interact with the execution environment to control and perform hot-swapping.