The xps program displays in an X Window the Unix processes as a tree
or forest, the roots of the tree are on the left-hand side and the
leaf processes (with no children) are on the right-hand side. The
status of each process (running, sleeping, stopped, etc.) can be
indicated by a color. Different users can appear as different colors
too.

Homepage:
https://motif-pstree.sourceforge.net/
