Welcome to the Visual Class Libraries (vcl) code source/ + the main cross-platform chunk of source inc/ + cross-platform abstraction headers / definition vcl/ + external headers generic/ + shared helper code for backends, actually built into vcl headless/ + a backend renderer that draws to bitmaps aqua/ + OS/X backend ios/ + skeleton Android backend win/ + windows backend unx/ + unix specific platform backend code and its' sub-platforms gtk/ gtk3/ kde/ generic/ - raw X