Customization and Flexibility in the exmh Mail User Interface

The exmh mail user interface is designed to be flexible and customizable. The goal in the design is to provide a platform that can be tuned to suit individual preferences, as well as extended to provide custom functionality. There are several mechanisms for customization: install-time settings define runtime support requirements; a Preferences user interface exposes various "knobs" and "dials"; the X resource database controls fonts, colors, and other widget attributes; a personal library of Tcl procedures supports new functionality; the buttons and menus in the interface are defined by X resource specifications to allow customization and access to personal Tcl extensions; hook points in the implementation support callbacks to user extensions at key moments in mail handling; A binding user interface defines editing and accelerator keystrokes. This paper describes these mechanisms, and provides some experiences in the use and development of exmh.