GRaph INterface (GRIN) is a powerful tool on the Graph theory with many capabilities for MS Win9X,Win NT, 2K, XP. System has an advanced user interface. EDITOR 500 points; Editor of the Graphs; Reports; ClipBoard; Decomposition of the Edges; Alignment of the Points; Export and Import to MS Excel file. SOLVER FOR PROBLEMSMetrics of the graph (Radius, Diameter, Density, Undensity and so on...); Paths and cycles (Eulerian and Hamiltonian); Bridges and cutpoints; Colorations (Point's Coloration); Authomorphism group; Minimal spanning tree; Shortest paths; K Shortest paths; Max. Capacity path;Salesman problem; Maximal flow; Critical path; Petri Net simulation.