Information is the foundation for creating active, functional systems at the smallest scales. Biology integrates information into nano- and microscale systems taking a bottom-up approach, starting with DNA to create proteins that enable advanced functionality. In order to build synthetic microsystems that can mirror the functionality of biology, we require a scalable information technology that can be integrated into top-down microfabrication schemes. In this thesis, we show that programmable magnetics is an invaluable tool for building a range of functional, information-rich microsystems capable of assembly and movement. We begin by presenting single domain nanomagnets that can be sequentially programmed for encoding information in microsystems. Using a hybrid fabrication strategy based on semiconductor manufacturing techniques, we integrate programmable nanomagnets into rigid micro-panels that can be released into solution and assembled via specific magnetic dipole interactions. We then introduce nanometer-thick membranes from atomic layer deposition. Utilizing their incredibly low bending energies, we employ ALD membranes as flexible scaffolding in shape-morphing micromechanical systems. Finally, we combine programmable nanomagnets and flexible glass membranes for adaptive magneto-mechanical systems that scale down to optical wavelengths. Throughout this thesis, we will address the applicability of these platforms to a variety of fields including self-replication, optical and mechanical metamaterials, and robotics.