With PreZentit, all you need is a Web browser to create a presentation with its own URL. You can download the presentation for display without an Internet connection. It has limited functions, but the ease of use makes it worth a try for on-the-spot pitches.
Convert your PowerPoint for the Web or create a presentation right within your browser. Prezi sets itself apart with the ability to craft interactive visual mind maps, use 3-D zoom, and turn your slides into a cinematic experience.
Anyone with a Google account can create presentations right inside Google Docs. You won’t find all the features available in PowerPoint, but it is free. It’s your best bet for collaborative projects because, like any other Google Doc, you can share it with others for real-time editing on the cloud.