Winamp is a media player for Microsoft Windows originally developed by Justin Frankel and Dmitry Boldyrev by their company Nullsoft, which they later sold to AOL in 1999 for $80 million. It was then acquired by Radionomy in 2014, now known as the Llama Group. Since version 2 it has been sold as freemium and supports extensibility with plug-ins and skins, and features music visualization, playlist and a media library, supported by a large online community.
Version 1 of Winamp was released in 1997, and quickly grew popular with over 3 million downloads, paralleling the developing trend of MP3 (music) file sharing. Winamp 2.0 was released on September 8, 1998. The 2.x versions were widely used and made Winamp one of the most downloaded Windows applications. By 2000, Winamp had over 25 million registered users and by 2001 it had 60 million users. A poor reception to the 2002 rewrite, Winamp3, was followed by the release of Winamp 5 in 2003, and a later release of version 5.5 in 2007. A now-discontinued version for Android was also released, along with early counterparts for MS-DOS and Macintosh.
After a five year hiatus, Winamp 5.8 (written as Winamp 5.



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) was leaked to the public in 2018 before its eventual release by Radionomy; development has since resumed with the latest version 5.9.2 released on April 26, 2023. Its developer Radionomy has since turned into the Llama Group in 2023 and launched a new Winamp streaming service, which includes a feature called Fanzone to "unlock the relationship between artists and fans". The service launched on the web in April 2023 followed by Android and iOS beta apps in July 2023.