General XML diff merge tool

I know that Eclipse/RTC has built in editors for things like build files and other files that store information in XML. They seem tailored to a specific XML dialect. I also see an external compare tool can be configured.

Is there any built-in tool that provides some level of XML comparison (versus basic line compare) between two XML files of any dialect? I'm looking form something that would allow DITA XML files to be compared/merged based on XML syntax versus line comparison.

Thanks, Brian