Two options here.
!. Name the output to .xml and bring it up in a web browser. Make sure the file is new-line delimited.
2. I wrote a script named xmlpretty. It may be in the contrib directory of the latest releases. If not, here it is. On Unix, rename to xmlpretty nad make sure it is executable. Also make sure firts line points to proper path for Tcl
It was a “quick and dirty” script so it may have problems with some of the more “fancy” things in XML. So far it has worked for me.