As science and technology continue to push towards new heights and the speed of innovation increases, DARPA’s interest in building common platforms, toolsets, and fundamental skills has grown. These have been long-standing tenets of FOSS, and DARPA believes that building an engagement between the two communities will allow both to benefit from and promote the use of advanced technology. DARPA’s Software Defined Radio (SDR) Hackfests are set up to engage a larger community than just the core developers of a project. While the DARPA Brussels Hackfest is aiming to address complex issues of software radio (SR) and the electromagnetic spectrum (EMS), these questions can only be answered by addressing a set of problems that span several fields and disciplines. Traditionally, software radio programming has been limited to a niche set of engineers and computer scientists specifically interested in this problem space. Yet a growing number of communities are identifying the utility of software radio. Software radio is successfully used in research, prototyping, and development of new wireless communications and radar systems. Today, the use of SR is expanding into fields such as information security and future cellular technologies. Security concerns in wireless are increasing due to the amount of data collected and transmitted through wireless Internet connections as well as the growth of the Internet of Things (IoT). As future cellular standards evolve quickly, adaptation must also occur quickly. Today, most cellular base stations are software radios, and much of the work going into massive multiple input multiple output (MIMO) is performed with software radio. The hackfests are designed as a way for DARPA to collaborate with a larger community of interested engineers and scientists working towards the future confluence of radio and information technology.