This paper describes a development environment for parallel scientific code. The environment uses Percolation Scheduling, a transformational system for parallelism extraction, and an interactive profiling system to give the user control over the parallelization process while reducing the burdensome details of architecture, correctness-preservation and synchronization. Through a graphical interface the user suggests what should be done in parallel, while the system performs the actual changes using semantics-preserving transformations. If a request cannot be satisfied, the system reports the problem causing the failure. The user may then help eliminate the problem by supplying guidance or information not explicit in the code.