CoreASM plug-in architecture Abstract State Machines are known for their versatility in modeling of algorithms, architectures, languages, protocols, and virtually all kinds of sequential, parallel, and distributed systems. CoreASM is a novel executable ASM language which emphasizes freedom of experimentation and supports the evolutionary nature of design as a product of creativity. The CoreASM engine, the heart of the CoreASM tool suite, is based on an extensible architecture which supports various extensions through plug-ins. In this paper, we explore the plug-in architecture of the CoreASM engine and demonstrate its potentials by looking into two implemented plug-ins.