The Carneades argumentation system is series of open source research prototypes, freely available for downloading at http://carneades.github.com.
For licensing information, see the particular release (below) of interest.
The following versions of Carneades are available, in reverse chronological order:
Carneades-4 The current version of Carneades, based on a new version of the Carneades Argument Evaluation Structures (CAES) formal model of argument. New in this version of CAES is much better support for cyclic argument graphs, cumulative arguments, practical reasoning, case-based reasoning, and multi-criteria decision analysis. This new model both generalizes and simplifies the previous CAES model. It also improves its compatibility with other models of structured argument, such as the Argument Interchange Format (AIF), ASPIC+ and IBIS (Issue-Based Information Systems). Carneades 4 is implemented in Go, a mainstream statically-typed, procedural programming language with a C-like syntax, garbage collection, good builtin support for concurrency and a large standard library. An inference engine, implemented using Constraint Handling Rules constructs arguments by instantiating argumentation schemes. License: MPL-2.0.
Carneades-3 (January, 2015) A multi-user web application version of Carneades, with a three-tier architecture, developed in the European IMPACT (2010-13) and MARKOS projects (2012-15). Implemented in Clojure and CoffeeScript. License: MPL-2.0.
Carneades-2 (October, 2011) A single-user desktop version of Carneades, implemented in Clojure for the Java Virtual Machine (JVM), and with a graphical user interface. Developed in a project with Doug Walton funded by the Canadian Social and Humanities Research Council. License: EUPL-1.1.
Carneades-1 (May, 2011) The first version of the Carneades engine, implemented in Scheme and developed in the European ESTRELLA project (IST-2004-027655) from 2006 to 2008. Also includes an experimental graphical user interface, implemented in JavaFX by Matthias Grabmair in a Google Summer of Code project. Licenses: LGPL-3.0 (engine in Scheme), and GPL-3.0 (graphical user interface in JavaFX).