Systems level liveness with extempore

Abstract

Live programs can be modified while the program is executing in order to provide a more reactive experience for the programmer. In demanding applications, such programs traditionally utilise pre-defined function calls to compiled libraries. We present a system that enables demanding live programs to be built where the supporting stack of libraries is, itself, live. In such situations, the top level code might be thought of as a simple ``live environment'' that can be created live and that encapsulates code that has ``bubbled-up'' from the supporting libraries. Our system enables this bubbling up to be achieved in an ad-hoc way and with minimal performance penalty. The deep, systems-level liveness that it exhibits is described and compared with other approaches to Live Coding and liveness generally.