CROSS-PLATFORM GUI'S : DEFINITIONS

PLATFORM: computer type, such as mainframe, sunsparc station, Macintosh or a PC.
Platform can also refer to different operating systems.
For example DOS and OS/2 are considered different platforms.

CROSS-PLATFORM: applications or files that can be used on different types of computers.
For instance HTML is a good example of a cross-platform standard for documents.

GUI: a user interface that utilizes windows and graphical widgets (buttons, icons, menus(pull-down, pop-up) etc.) to represent commands.

PIGUI:

Platform Independent Graphical User Interface
aka cross-platform GUI, portable GUI
interactive software library toolkit that enables application developers to produce GUI code for multiple computer systems
only deals with the GUI aspect of the application
other portability issues are the developer's problem.

API: Application Programming Interface. Its what the programmer sees when using a software development toolkit; normally this would include a set of function calls and/or objects.

CORE CODE: includes the basic operations common across all platforms.

EDGE CODE: those parts of a program that deal with platform-specific issues.