Windows and forms
Programs manipulate window and form objects to define display areas controlled by interactive statements.
The forms are defined in text-based form specification files (.per). These form files are transformed by the fglform compiler to produce the runtime form files (.42f) that are deployed in production environments. The resulting (.42f) files are XML documents that describe the form elements, enabling portability across display devices. The XML file can also be written directly, or it can be generated or modified from your program at runtime with XML utilities.