1. A computer-implemented system for generating a graphical user interface for an application, comprising: a computing device that includes a display screen for use in displaying a graphical user interface for an application; an application source code file, that specifies an application logic that is executed by the application; an application interface file that specifies a plurality of graphical elements within an interface library to be displayed for the application graphical user interface; an interface grammar file that specifies rules to be used in parsing the application interface file; the interface library that comprises a plurality of graphical elements that are selectively retrieved in accordance with the specifications of the application interface file and the interface grammar file; and a parser that parses the application source code file, application interface file, and interface grammar file, wherein the parser determines within the application source code file a reference to the application interface file, determines by reference to the interface grammar file whether a function call specified by the application source code file is allowed, and communicates the function call to the interface library, to retrieve graphical elements from the interface library, and generate the application graphical user interface.