GraphClustering is a C# GUI for data mining and clustering research. In particular, this implements the graph based resilience measure Vertex Attack Tolerance (VAT) and the adapted clustering algorithm Hierarchical VAT Clustering (hVATClust). The NetMining library provides many other common clustering algorithms (K-Means, SOM, Girvan-Newman, etc.), Several ADTs (Quadtree, Heap, DisjointSet), Dimensionality Reduction, Data Generation, and Internal(Dunn, Silhouette, Davies–Bouldin) and External Clustering evaluation.