WaJapi is a java-api to winamp, it is possible to invoke several functions like start, stop, skip, etc plus query the media library please note that a Winamp plugin named ActiveWinamp is necessary
An automation plugin for Winamp. This exposes a lot of winamp functionality through COM / ActiveX. You may use this to write VB or .NET or any other applications which interact with Winamp. Also supports internal script hosting.