TREEBAG is a system that allows to generate, transform, and display objects of various types, where generation and transformation is done using tree grammars and tree transducers. The basic principle is that tree grammars produce terms over symbols that are interpreted by appropriate algebras as operations on some domain. Thus, every term is viewed as an expression that denotes one of the objects of interest. These objects can be visualized using appropriate displays. For more information, please have a look at the technical report on TREEBAG (report 1/98, Department of Mathematics and Computer Science, University of Bremen) and the TREEBAG manual. If you can read Spanish, you may also wish to have a look at two contributions to the International Conference of the Chilean Computer Science Society 2002, both authored by M. Aguirre, E. Jeltsch, and G. Rosales: Generación de Formas Pictórias sobre un Sistema de Inerencia a través de TreeBag and Aplicaciones en TreeBag
TREEBAG is written in Java. The user interface of the current version 1.2 is based on Java 2. It will not work if you use JDK 1.1 or 1.0.