InteractiVenn is a web-system for the visual analysis of lists of elements through Venn diagrams. Its main feature is the capability of allowing union operations between sets while keeping the visual map of the diagram. That is, when we perform the union of 2 sets, instead of going from a diagram with 3 circles to a diagram with 2 circles, we maintain the layout and apply the union to the shapes as well.
The published article was considered highly cited already in its initial 1-2 years. The tool have many access daily and facilitate the analysis of many scientist and other professionals. I think what makes this tool incredible is its simplicity and clean design, easy to use and extremely usefull.