Windows Longhorn was Microsoft's codename for the operating system in development during the early to mid 2000s, before it was released as Windows Vista in 2007. Sounds from its test builds circulated among enthusiasts who archived system files, wallpapers and startup tones from leaked versions. The USB in tone survived in that collecting culture and later appeared on soundboards as a nostalgic alternative to the familiar XP and Vista alerts. It remains popular with retro computing fans who prefer its softer design.