DiffLibrary is a Robot Framework test library that will provide keyword functionality to diff two files together

Install robotframework-difflibrary

pip install -U robotframework-difflibrary

DiffLibrary uses the external diff executable that is avaible on most Linux systems out of the box. It also comes packaged with GNU diff binaries for Windows. This is to work around the problem described in the following issue;

http://code.google.com/p/robotframework/issues/detail?id=497

python -m robot.libdoc src/DiffLibrary/ doc/DiffLibrary.html