This is a great idea: a project management system that works like developers think - by coding. I spell out my resources, constraints, tasks and deliverables using a simple programmer-friendly syntax, and TaskJuggler compiles my "program" into a plan, with all the necessary communication artifacts like Gantt charts.
Armed with this, I can make better estimates and understand the challenges facing a complex project. As the project moves forward, it's easy to enter actuals and compare to a baseline, and make new plans where needed. Plus, since the project plan exists as a straightforward text file in program-type syntax, it's beautifully susceptible to revision control, modification by external software, etc.
Like many developers I know, I have often used project management software the opposite way -- making a plan in my head, then coercing the software to document it. TaskJuggler really helps make a plan, not just document one.