Agent Development Environment (ADE) is a multi-agent system (MAS) middleware intended for the design, implementation, and testing of distributed agent architectures with special emphasis on complex robotic systems and human-robot interaction (HRI). Available for both Unix-based platforms and Windows based platforms, ADE has an extensive code base that consisted of both infrastructure components as well as implemented components with specific functionalities (e.g., audio and vision processing components, planning components, reasoning components, natural language components, etc.). ADE appears to have been last developed in 2011.