GVim can show two (or more, I believe) files like that in panes, but I don't know if they will scroll at the same time.
Have you looked at sdiff? Doing something like:
sdiff ./File1.txt ./File2.txt | less
Would do what you want, unless you need/want it to be GUI based.
I just checked, and you can easily open multiple files in different panes in GVim, but they scroll seperately, unless there is an option to link them together, but nothing jumped out at me that would seem to do that.
Last edited by MS3FGX; 10-20-2006 at 04:56 PM.