This paper overviews the Defense Advanced Research Projects Agency (DARPA) Adaptive RF Technologies (ART) and Arrays at Commercial Timescales (ACT) programs. These programs seek to create adaptable and reusable RF hardware in order to lower nonrecurring engineering development costs and timelines for RF systems and to allow RF hardware to be adapted to new missions after fielding. To achieve this vision, new RF architectures more amenable to reconfigurability have been developed along with component technologies that reduce the performance penalty associated with adaptive RF hardware.