Greenfoot

Greenfoot is an integrated development environment for the Java language, arranged for people who are still learning to program. Instead of beginning with a bare console project, work is framed around programs that produce visible output: graphics, animation and sound belong to the ordinary vocabulary of an exercise, so the effect of an edit in the source code can be observed directly rather than inferred from printed text.

The environment brings editing, compilation and a view of the running program together in one window, which suits classroom sequences as well as self-teaching. It is published by King's College London and distributed under GPL-2.0-or-later with the Classpath exception, a combination that allows the accompanying libraries to be linked without the licence extending to a user's own code.

The entry here describes the Linux packaging; no build for other operating systems is listed alongside it. Readers looking for a general-purpose Java IDE for production work will find the emphasis on teaching visible throughout.