OpenOffice Impress is a free multimedia presentation tool suitable for creating slideshows. LibreOffice Impress also has similar functionality. Alternatively, Slides.com provides a free option for creating slideshows and storing them in the cloud.
OpenOffice and LibreOffice are sometimes compared to Microsoft Office. LibreOffice Impress includes features not present in PowerPoint, such as an option to export presentations to HTML. These office suites are designed to serve as completely free alternatives to Microsoft Office.
The free option on Slides.com limits users to 250MB of storage and public hosting only. However, Slides.com is based on a free HTML presentation framework called reveal.js. Tech-savvy users can use this free framework to directly create slideshows without any restrictions.