Stretching DNA is a tool for scientific purposes (and, also, totally free), because it is a utility that simulates the stretching of a DNA sample, using optical tweezers.
What Stretching DNA really intends to demonstrate is the relationship between the length and strength of the DNA stretch, as well as the force needed to keep it stretched. The user can change the different parameters and elements to see how the graph varies.
For the proper functioning of Stretching DNA you need to have previously installed Sun Java 1.5 or higher.
You can free download Stretching DNA 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.