GeoGebra
This is where I will put GeoGebra files, and links to GeoGebra files. GeoGebra is free software with many components: geometry, 3D geometry, graphing, CAS, and spreadsheet. It is available for pretty much all platforms on computers and tablets as well as online through a browser.
We will not have time to install software during the workshop, and at any rate, you will not need to use it in the Hands-On Geometry workshop. (I will use it to illustrate some ideas.) Most of the files I plan to use can be accessed online with a browser. If you want to use GeoGebra files offline, you can download the application here. There are huge numbers of possibly useful GeoGebra files here, but I'm not familiar with them.
Here are some of the figures I might use in the workshop — if I end up using more, I'll add them.
Isometries (Rigid Motions)
To explore some other things I've done with GeoGebra, go to my Applets Directory.