Powerpoint, Keynote and some lesser-known desktop applications were for a long time the only choice for creating presentations.
Even though there are other ways to share your experience with the public, presentations still remain the key way of delivering structured content to the audience in a short time.
Recent technologies like Html5/Javascript/CSS3 and Markdown allow developers to throw away clumsy UI and start creating content that is easy to version, to merge, to restyle and to collaborate