Stack Overflow - Community-based Q&A part of the Stack Exchange platform.
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.
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
Microsoft PowerPoint - Microsoft PowerPoint empowers you to create clean slideshow presentations and intricate pitch decks and gives you a powerful presentation maker to tell your story.
Askalot - Askalot is a next generation CQA (Community Question and Answer) system.
Google Slides - Create a new presentation and edit it with others at the same time — from your computer, phone or tablet. Free with a Google account.