JigAdmin is the Jigsaw Administration Tool, it's a graphical interface that communicates with an Administration server, called JigAdmin Server. This server can administer multiple Jigsaw servers running on the same machine, provided those servers has been launched at the same time (means by the same java VM). This version of JigAdmin is built with Swing Components, so it's more beautiful and user friendly (ie: Drag and Drop feature). Here is the documentation of the old JigAdmin (for JDK1.1.x users).
some snapshots (visual index).