The Spanning Tree Protocol is used to interconnect network switches, based on an algorithm invented by Radia Perlman. She also summarized the algorithm in the form of a poem, titled "Algorhyme".

 I think that I shall never see
 A graph as lovely as a tree.
 A tree which must be sure to span.
 So packets can reach every LAN.
 First the root must be selected.
 By ID, it is elected.
 Least cost paths from Root are traced.
 In the tree these paths are placed.
 A mesh is made by folks like me.
 Then bridges find a spanning tree.