[XeTeX] Alternative to tree-dvips?

[Jonas Wellendorf]

Tree-dvips is incompatible with pdftex, so I am looking for an 
alternative I can use with xetex.  The document I am typesetting 
requires me to draw arrows such as this one:

I would like to have an arrow from here to here
                                                                   |     
          ^
                                                                   
|______|


Thank you,
Jonas W.