Review on Tortuga by Tony Wylie

The ability to model all types of systems, from small problems to large complex ones. It's also very easy to use. I like that it's free and open source. There are some things that could be improved, but not enough to make me dislike it. Sometimes it takes a while to figure out how to do something, so if you're new to this, take your time and read through the documentation. If you have any questions about how to use the program, just ask someone who knows how to use it. This program has helped me with many different types of problems. From inventory management to financial models, this program has been great.