Diff.Net is a differencing utility I wrote in C#. It provides side-by-side differencing for files and directories. For files it also provides an overview diff and a line-to-line diff. And it can do a visual difference of binary files.
This software is CharityWare. If you use it, I ask that you donate something to the charity of your choice. Its binaries and source code are licensed using the MIT license.
Click here to see a screenshot of file differencing.
Click here to see a screenshot of directory differencing.