The XASM runtime system implements the core functionality of the XASM language. In here, all algorithms and data structures are realized being used to transform an ASM into an executable program. At the heart of the runtime system is the implementation of update and access functionality for ASM functions. For that, a hashing mechanism is used to provide optimized access to values of ASM functions. The runtime system also contains garbage collection facilities, which is indispensable, if ASM algorithms are used for continuous control systems, as described in [4].