sentences:  The original version, first released in 1997, uses Adobe Shockwave.In January 2007 version 2.0 version was developed for Microsoft Vista using a browser-based Windows Presentation Foundation format.Features include page turns that are modeled on the actually deformation of different types of material (for example in a book with vellum pages, which is heavier than printed on paper, will appear to collapse under its own weight as it is turned).