I downloaded the demo/trial and was excited about the difference explorer but when it always displayed the message about "not available" I assumed it was a Pro feature so I purchased the full version only to see that it still tells me "not available" - my bad.
Anyway. I'm requesting that you add Pascal support in the difference explorer seeing as you do have Delphi language support for syntax highlighting.
Request: Pascal support for Difference Explorer
We will consider this request in the future versions. Also you can submit your idea at http://devart.uservoice.com/forums/93035-codecompare