Our new SimUText project, funded by an SBIR grant from the National Science Foundation, is a major innovation in student learning of biology. It takes one pillar of typical biology classes, the textbook, and transforms it from a passive reading exercise to an active and engaging learning activity. Students using SimBio Interactive Chapters within SimUText cover similar material to what is in traditional textbooks, but along the way they must apply what they are learning to do simulated experiments, answer questions, and interact in other ways that let them learn-by-doing. Visit our pages describing SimUText for more information. Or look at our SimUText Ecology series of modules to see how you could replace your ecology textbook with something better.