Microsoft PowerPoint is far and away the most widely used presentation program.
Apache OpenOffice Impress is a free and open source alternative to PowerPoint. It is part of the productivity office suite Apache OpenOffice.
OpenOffice Impress is a presentation tool. The software is open source so free and legal to download and install for both private and business users.
Apache OpenOffice Impress has the following characteristics:
Apache OpenOffice Impress screenshots
You can free download OpenOffice.org Impress and safe install the latest trial or new full version for Windows 10 (x32, 64 bit) from the official site.