Ginga-NCL: the declarative environment of the Brazilian digital TV system

as in all main terrestrial dtv systems, the brazilian middleware, named ginga, supports both declarative applications (through its presentation, or declarative, environment ginga-ncl) and procedural applications (through its execution, or procedural, environment ginga-j). since hybrid applications are common, either type of ginga application may make use of facilities of both presentation and execution application environments. this paper focuses on the presentation environment ginga-ncl. the main brazilian inovations are then presented, regarding the ginga architecture, the declarative ncl language specification, the editing commands for live application production, and the transport data structure.