Altova DiffDog Professional Edition allows you to diff/merge of text files, folders, and directories. It also includes XML-aware comparison options.

Altova DiffDog Features

File Comparison

Compare any text files and indicate differences with colored highlights and connecting lines

Bi-directional merging of individual differences and direct editing of files in comparison window

Unlimited Undo/Redo for editing and merging

Saves file selections in a comparison settings document for reload later

XML Comparison         

Multiple options for XML-aware comparisons, such as entity resolution, ignore attribute order, etc.

Well-formedness checking and...