Working on this project I have come to the conclusion that the documentation surrounding the Winamp API is a total mess.
My first task is going to be to establish a clear documentation on the different ways to interact with the Winamp API with the objective to make it easier for anyone looking to expand the features of this beautiful application. We are in dire need of an updated API/SDK and working code examples if we want to see more people developing plugins.
This is in no way, shape or form a critic of Dro's work. Without him, none of us would be here. On the contrary I praise the work he's done and the efforts he put into keeping this project alive. Hopefully I can contribute a little with this.
Feel free to add to this thread information or links to the source code of plugins working with Winamp 5.55 / WACUP. I'll do my best to document the functions and try to come up with a comprehensive guide to interact with the various part of the app.