2.1. Argo UML

Like Umbrello, Argo[argo] started as an academic project and, like Umbrello, it is openly developed Free Software. It lists cognitive support as one of its differentiating features. In practice this means several innovative features inspired by theories on human cognition during design tasks:

• Critics - model design is continuously reviewed by plugin "critics", for example if a class inherited from two other classes a Java critic would display a warning that this is incompatible with Java.

• To Do List - Critics, UML diagram widgets and users can add items to categories within a To Do list which is continuously displayed. This mirrors the lists commonly used by software engineers when performing common tasks.

• Non-modal Wizards - wizards to guide developers though common tasks, which can be paused, stopped and resumed at any time to keep the user in control.

• Table view - diagrams can also be viewed as tables showing the relationships between diagram elements.

While Argo has many original features such as those above it has a poor user interface. Being written in Java it is slow, unresponsive and is inconsistent with the surrounding desktop. It is also not considered to be stable software, having not released a 1.0 version.