Leogo (1997) - Cleogo(1998)

Leogo is a novel programming environment supporting an `equal opportunity' user interface which allows users to express their programming tasks through any mixture of three concurrently active programming paradigms: by direct-manipulation using `programming by demonstration', by clicking buttons and dragging sliders in an iconic language and by typing commands in a normal text-based language. Equal opportunity ensures that the effects of any interface action are simultaneously displayed across each of the three paradigms-input expressions in one paradigm cause output of equivalent expressions in the other two paradigms.

Cleogo is a novel groupware environment that allows several users to simultaneously develop programs through any mixture of three alternative programming metaphors: a direct manipulation language for programming by demonstration; an iconic language; and a standard text-based language. Cleogo is motivated by the pedagogical values of peer-learning and of collaborative problem solving, and by our desire to investigate flexible and appropriate user-interfaces for programming, particularly for youthful users.