Macromedia Flash File Format (SWF) SDK provides a set of tools for developers to write Macromedia Flash (SWF) version 4 files. Macromedia Flash File Format (SWF) SDK is comprised of a low level interface and a high level interface, both of which write SWF files, but are intended to be used in different ways. The low level manager has been designed to follow the structure of SWF as closely as possible. It includes a set of C++ classes that mirror the tag structure of SWF. There is a C++ class for each tag that SWF defines. The high level manager provides a higher level of abstraction for creating SWF files. High level classes begin with the prefix HF. There are HF classes for creating movies, frames, circles, rectangles, text and bitmaps. High-level classes are much easier to use than low-level classes. For example, the HFCircle class creates a circle using a center point, and radius. There is no need to construct the circle with curved shape records.