For those people using XMetaL's TopLeaf Plugin to generate PDF output, a new recipe has been posted in the online documentation describing how to display change tracking in PDF output.
Link to recipe. http://na.justsystems.com/webhelp/en/topleafplugin/6.0/TopLeafPlugin.html#How%20To%20Display%20Tracked%20Changes%20in%20PDF%20Output
Change bars are shown on the left.
Deleted text is shown in red with a strike through.
Added text is shown in blue.