IBM Generalized Markup Language

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IBM Generalized Markup Language (GML) is IBM’s early system of tags for procedural markup used with the IBM text formatter SCRIPT. It lets you mark up a document to define its structure—paragraphs, headers, lists, tables—and then format it automatically for different output devices (laser printer, dot matrix, or screen) by applying a device profile, without changing the document.

GML was created around 1969–1970 by Charles Goldfarb, Edward Mosher, and Raymond Lorie (the name GML comes from their initials). It influenced SGML, the ISO standard for defining generalized markup languages, and SGML in turn influenced XML.

In the early 1980s IBM built ISIL (Information Structure Identification Language) based on GML to generate IBM documentation for PCs and other products. Later, BookMaster was developed largely on ISIL. Don Williams at IBM also created DWScript to use SCRIPT/VS on the PC, and in 1986 he produced DWISIL, a PC version of ISIL. These tools were mainly for internal IBM use.

Today, IBM uses GML as a description language on IBM i and related systems for objects called “panel groups.” Panel groups can show just help text when you press F1, resemble IBM i menus with embedded help, or display full application screens with input/output fields, all formatted according to IBM’s CUA standards. The whole system is called the User Interface Manager (UIM) and is described in Application Display Programming.