A collection of XSLT files for all sorts of purposes.
Each transform has been tested with Saxon-HE for Java. You can run Saxon directly from the command line like this:
java -jar Saxon-HE-10.0.jar -xsl:transform:.xsl -s:source.xml -o:output.xml
Any other XSLT processor supporting XSLT 3.0 should work as well. If you want to test them online, you can use XSLT Fiddle.
kml_sort_placemarks_alphabetically.xsl sorts the Placemark elements inside of a KML document in ascending alphabetical order. The Folder elements themselves are not reordered, only the Placemark elements inside each Folder element.