AptDiff

AptDiff is a visual text/binary files comparison and merging utility for Windows 2000/XP/2003/Vista. It is highly useful for software developers, web designers and other professionals. Full unicode support. This program displays two files side by side, highlighting the differences. It's clean and Easy.
-Compares directly from Windows Explorer.
-Easy navigation through the differences.
-Automatically detects file changes.
-Customizable keyboard shortcuts.
-Adjustable pane splitter with smooth synchronized scrolling.
-Synchronized horizontal and vertical scroll.
-Command Line Support.
-Automatically move to the first difference when loading.
-Merge all for text comparison.
-Switch the comparison type between text and binary.
-Add the shell menu items ("Select First Item to Compare...", "Compare As Text", "Comapre As Binary") if enabled in options.