Software systems that allow the user to effectively exploit parallelism in an architecture are rare. This is a report on three software development tools designed for the DRAFT horizontally reconfigurable architecture machine: reconfiguring microassembler, a debug simulator, and an operating environment. In all of these tools a high priority has been placed on ease of use and minimization of the programmer's responsibility for management of parallelism. At the time of this writing, the first two of these tools have been implemented and are currently in use. The operating environment, like the prototype machine, is in the final stages of construction.