Haiku is an open-source operating system that specifically targets personal computing.
Inspired by the BeOS, Haiku is fast, simple to use, easy to learn and yet very powerful. Additionally, Haiku offers something over other open source platforms which is quite unique: the project consists of a single team writing everything from the kernel, drivers, userland services, tool kit, and graphics stack to the included desktop applications.
For each item you purchase, we donate part of our profits to Haiku Project. This way we all win :)
More information: https://www.haiku-os.org/