one of the things I hate about xml, is that without syntax highlighting its very hard to see which directives are commented and which live.
This is often a problem, when you are in root profile, on some tomcat box, and you are inspecting the server.xml for changes...
tidy[]
tidy -quiet -asxml -xml -indent -wrap 95 --hide-comments 1
xmlstarlet[]
xmlstarlet c14n --without-comments old.xml > new.xml
xmllint[]
xmlllint --format
sed[]
cat <XML_file> | sed 's///' | sed '//d'
http://www.prasannatech.net/2010/12/stripping-comments-xml-file.html