eXist comes with a "debugger" extension (or "debuggee", depending on which area of the code you look in), which is disabled by default. To enable XDebug in an eXist application:

1. Build and deploy eXist: http://hcmc.uvic.ca/blogs/index.php?blog=11&p=8146&more=1&c=1&tb=1&pb=1

   • Important:When editing local.build.properties, set include.feature.debugger to true

2. Copy:

   (exist source directory)/extensions/debuggee/lib/mina-core-x.x.x.jar

   To:

   (exist deploy directory)/WEB-INF/lib

Part two will cover actually using the debugger to step into a running script, once I figure out how to do that.