Sorry but the project you downloaded is now obsolete.
We released next generation GroupDocs.Comparison for .NET API that is totally UI independent. Learn more about environment and installation details here.
This API can be integrated in any .NET application without platform or any third party tool dependency.
Now document comparison is way simpler.
//Source and target files to be compared
string source = @"source.docx";
string target = @"target.docx";
Comparer comparer = new Comparer();
//Compare two documents
ICompareResult result = comparer.Compare(source, target, new ComparisonSettings());
We also have some useful resources for you: