Here's a solid demo of the free OS, Haiku, which is based off of BeOS. They've brought it up to date so it runs Firefox, GNU Imp, and LibreOffice. Not shown but kind of awesome are filesystem queries integrated into the wm, Tracker, which is one of my favorite OS/wm features from any platform. If you've not tried Haiku then I recommend downloading an ISO and running it in a VM. https://youtu.be/1R4WCaOpmlo