Two other algorithms are commonly used today. One of them was developed by Vojtěch Jarník in 1930, and put in practice by Robert Clay Prim in 1957. Edsger Wybe Dijkstra rediscovered it in 1959, and called it Prim's algorithm. The other algorithm is called Kruskal's algorithm, and was pulbished by Joseph Kruskal in 1956. All three algorithms are greedy, and run in polynomial time. 