<p>Casual is a free, open source tool for generating a visualization of concepts from a key word search. It uses Wikipedia for conceptual information, and can also include Google Image search results where applicable. Users can click on a term to generate a new search from that term, while image results can be rearranged by clicking and dragging them to the desired location. Casual can produce visualizations ranging from 10 to 400 concepts in size, and can retrieve information for queries in a wide variety of languages. This tool is no longer supported; development appears to have ceased in 2009.</p>