Trying out OPENPROJ

I am taking a chance and trying out the free project software called OPENPROJ. It seems to be almost in the beta state. But it may just be that I am having trouble finding the documentation. In any case I have loaded about 120 project/tasks into the System and so far it seems to have accepted them without crashing. I haven't yet figured out how to adjust the scale on the Gantt chart. I can only see a few months at a time. I need a scale that shows about 15 years. I am not completely clear on how the precendents work. It does not seem to allow progress to be dependent on more than one prior task. But, again, it may just be a matter of finding the documention. The same outfit that offers OPENPROJ offers another more comprehensive system (ON DEMAND I think) that lets the project to be run on line with many teams involved. We may have to convert over to that kind of system when the number of actual participants grows. They want about $20/mo for the system.