In 1998, David Hill envisioned an online resource that would connect mathematics instructors with technology-based, interactive demonstrations for teaching and learning mathematics. The time that instructors have to prepare for technology-enhanced lessons is short so a collection of ready-made demos with suggestions for how the demo can be used in class would be an outstanding resource for instructors. With partial funding from the National Science Foundation, Dave Hill and Lila Roberts made Demos with Positive Impact a reality. Over the years the Demos project has been used by countless instructors all over the world.

After more than 20 years, we have decided to retire the main Demos with Positive Impact collection and we want to keep the project alive by continuing to share some of the most-used, along with some new and refreshed versions of old demos. Since the project started, there have been many improvements in available technologies. A large number of web-based projects have been developed over the recent years that embody our original vision. This affirms our belief that our original objective was right on target: create and share instructional tools that use technology to enhance the learning experience.

We hope you will enjoy the new site and that you will be able to incorporate these tools into your mathematics teaching.