Windows Longhorn was Microsoft's codename for the operating system project that eventually shipped as Windows Vista in 2007 after a long, famously troubled development. Dozens of interim Longhorn builds leaked or circulated among enthusiasts, and their startup sounds, wallpapers and interface experiments became collector items in retro computing circles. The logon chime survives on YouTube compilations and soundboards, where a niche but loyal audience of OS nostalgists keeps it alive. It endures as an audio relic of the most mythologized unreleased Windows era.