Haiku, originally OpenBeOS, is a free and open-source operating system for personal computers. It is a community-driven continuation of BeOS and aims to be binary-compatible with it, but is largely a reimplementation with the exception of certain components like the Deskbar. The Haiku project began in 2001, supported by the nonprofit Haiku Inc., and the operating system remains in beta.

• I would be pleased to see Haiku flourish, if only because someone chose to do so. Sometimes, you need those kind of efforts. Quixotic. But they make the world a happier place, simply by the grace of their quirky existence
  • Dedoimedo, Haiku Alpha 4 - So what's next? September 2013
• Haiku is a true eye-opener for me. It shows how a desktop can “just work”. In many aspects this system is exactly addressing what has been driving me crazy on the “Linux” desktop for well over a decade, as someone originally coming from the Mac and looking for the same level of elegance and simplicity.
  • probono, My first day with Haiku — shockingly good! July 2019