Araucaria is an argument mapping software tool developed in 2001 by Chris Reed and Glenn Rowe, in the Argumentation Research Group at the School of Computing in the University of Dundee, Scotland. It is designed to visually represent arguments through diagrams that can be used for analysis and stored in Argument Markup Language (AML), based on XML. As free software, it is available under the GNU General Public License and may be downloaded for free on the internet.

The user interface is composed of a main window (diagramming), a schemes editor and the AraucariaDB online interface.

When a text file is loaded into the program, the text is displayed in the left-hand panel of the main window. Highlighting portions of text before clicking on the right (larger) panel creates corresponding nodes at the bottom of that panel. Nodes can then be paired together by dragging one (which will be the premise) to the other (the conclusion). To each node may be attached a value such as the ownership of the proposition, or an evaluation specifying the degree of confidence placed in premise. Similarly, symbols can be added to the arrows to state the strength of the inference. In addition, the user may link arguments, supply missing premises (argument reconstruction) and use refutations. The diagram will always take the form of a tree structure in Araucaria. The user has the choice of translating the argument into standard diagram, Toulmin diagram or Wigmore diagram, Araucaria 3.1 being the first software to integrate the latter ontology and to address the translation issues between the different diagrams.

While Araucaria helps identify the structure of an argument, it provides freedom of analysis resources. The scheme editor allows the user to create argumentation schemes, group them together and save them into a scheme set file. The scheme set is then applied to the diagram, entirely or in part. As an illustration, an argument scheme relying on symptoms could be applied to the following assertion: "The light has gone off. Therefore, the bulb must be broken", with critical questions intended to determine if the result could stem from another reason (such as "have all the lights in the flat gone off?").

The AraucariaDB Online Repository can be browsed to retrieve specific arguments to fit a diagram. Alternatively, an argument diagram, along with annotations, can be saved into the database.

Araucaria was developed in Java in order to be supported on most platforms. It is licensed under the GNU General Public License and complies with free software standards. Argument Markup Language (AML) was created to maintain the evolving relationship between text and diagram. To this end, tags are added to the text and specify the connection between each component. AML is designed to be an application of argumentation theory in artificial intelligence.

Because it is based on XML, a standard widely used by developers, AML content can be accessed through other software that support XML. Likewise, AML data is easily available online after using style sheets to create HTML web pages.

Araucaria itself is conceived to be compatible with other tools. One example of integration is the argumentation software library Argkit. The online corpus provision is an extension of the Araucaria project. Further integration is planned with other applications currently under development.