CSDiff

Automatically discovers the differences between the files that it's comparing and displays a list with all dissimilarities that it finds. The tool works with source code files, HTML files as well as regular documents and it's most useful for people working on collaborative projects who want to know what has been changed.

ComponentSoftware Diff (CSDiff) is a free, advanced file-difference analysis tool for Microsoft Windows. CSDiff is a great asset to anyone in need of analyzing changes which have been made between two revisions of the same file or folder. CSDiff is commonly used when analyzing program source files, HTML documents and MS-Word documents.
Key features in CSDiff: