Diff Checker - Diff Checker is a free online diff tool that quickly and easily gives you the text differences...
Beyond Compare - Beyond Compare allows you to compare files and folders.
DiffNow - DiffNow lets you compare text files, documents, binary files, and archives up to 1024KB in size.
Content Compare by DeltaXML - Content Compare is the #1 comparison solution for specified XML grammars. Simplify your workflow and detect differences quickly and accurately with DeltaXML’s Content Compare. Find changes between XML content, ensuring error-free XML comparison.
Araxis Merge - Home of the award-winning Araxis Merge two and three-way file comparison (diff) and merging application, Araxis Find Duplicate Files, Araxis Replace In Files, and the Araxis Ketura issue tracking, project scheduling and time tracking application.
Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.