Jade is an environment that supports the development of distributed software. Components may be written in any of a number of different languages. A common inter-process communication protocol provides a uniform interface among the components. A window system allows the user to interact with many different processes at once and allows for multiple views of the same process. A hierarchical graphics system is provided for use with documentation and programming, and for support of monitoring. The non-determination of distributed systems may be controlled in order to provide repeatability of executions and to aid in prototyping real-time distributed software. Finally, the formal specification of inter-process events in Jade is supported by a communications protocol verifier, allowing run-time consistency checking. We describe these tools and their use in the development of distributed software for the control of a simulated system of parking lots.