Winamp 5
Nobody wanted to see a Winamp 4 skin (get it, foreskin), instead the Winamp 2 and Winamp3 branches were fused into Winamp 5. This versino was based on the Winamp 2 codebase, and included several Winamp3 features, such as modern skins. It was released in December 2003.
Versions 5.2 onwards included built-in support for synchronizing with an iPod.
Winamp 5.5
10 years after the first release of Winamp, Winamp 5.5: The 10th Anniversary Edition was released (October 10, 2007). We now saw album art support, improved localization support, including official German, Polish, Russian and French releases) and a unified media library interface and player skin. This version is also noted for dropping Windows 9x support.
Easter eggs
Speaking of history, Winamp has always included a number of Easter eggs in their releases. Case in point: an image of Winamp’s original author Justin Frankel hidden in Winamp’s About dialog box.
Legal History
According to Tomislav Uzelac, Frankel, one of the program’s original authors, licensed the AMP 0.7 engine June 1, 1997. Frankel founded Nullsoft, Inc. in January 1998, and continued development of Winamp, which was sold as shareware for $10. In March 1998, Uzelac’s company, PlayMedia Systems, sent Frankel / Nullsoft a cease-and-desist letter, using unlawful use of AMP as its basis. At the time, Nullsoft responded that they had replaced AMP with Nitrane, a proprietary decoder, which PlayMedia didn’t buy. PlayMedia Systems ended up filing a federal lawsuit against Nullsoft in March 1999, and Nullsoft had to halt distribution of Nitrane. Later that month, the lawsuit was settled out of court, and shortly thereafter, Nullsoft began using an ISO decoder from the developers of the MP3 format, the Fraunhofer Gesellschaft.