Hi Linda, It sounds like you are looking into some neat stuff! I can't help with everything you are studying, but I have been using the Geometer's Sketchpad for a few years and have found that it has really changed my approach to geometry. I originally thought of the sketchpad as a piece of software but now see it as an environment for exploring, discovering and learning. To classify it as software just seems to be too limiting. I also use the text published by Key Curriculum Press, "Discovering Geometry". This text, together with support material available for the sketchpad, is a great start for a discovery approach to geometry. I had taught geometry for more than 20 years using the formal proof approach that I learned in my high school. I admit, the transitional time had it's difficult moments. I questioned many things but tried to remain open to the approach. I was very satisfied with my first year using the sketchpad, but it took a second year through the text before I completely understood the discovery approach. At first glance, it can look like a course with little substance. The text does not have a list of theorems or a glossary of terms to memorize - but as the course develops, students mold the definitions and develop the theorems - kinda like the real thing, huh? Now, I realize that my students are learning so much more about geometry. I am sold on this approach to geometry! I know the other software you mentioned have strong points as well, however the success will be dependent more on the use of the material - not the material itself. Whatever you select, be sure to think of it as more than software - you will call it software, and I will call it software - but you are actually selecting a learning environment. In the early 80's, Seymour Papert wrote about microworlds as incubators for knowledge. Today we have these incubator packages that allow us to create these worlds for exploration. Please keep us informed about your decisions - it's only in sharing experiences that we can grow. Good luck and have fun exploring!