A structured APL system introducing several interesting features is described.The APL group concept has been considerably extended to yield a new type of APL object called a segment.Segments constitute the basic building blocks used to manage memory and to build up the workspace and the user's library.The encapsulation capability provides a unified scheme for handling variables, functions, and other APL objects, including fries.A new structured user library is proposed.The dynamic call of objects during a terminal session links the user library to the workspace.New types of variables are described along with solutions to interesting problems based on them.