Apple Keynote - Apple Keynote or just Keynote is an advanced level presentation software application created as a part of the iWork productivity suite by Apple Inc.

Slidebean - Presentations that design themselves

SlideShare - Discover, Share, and Present presentations and infographics with the world’s largest professional content sharing community.

SlidesPPT - Beautiful free presentation templates for Google Slides

Prezi - Welcome to Prezi, the presentation software that uses motion, zoom, and spatial relationships to bring your ideas to life and make you a great presenter.

Slides - Slides is a place for creating, presenting and sharing presentations. The Slides editor is available right in your browser. Unlike traditional presentation software, like PowerPoint, there's no need to download anything.