What else can I do with DiffNow?
DiffNow also lets you compare:
Microsoft Office documents (doc, docx, xls, xlsx, ppt, pptx)
Source code in C, C++, C#, Java, Perl, PHP, and other languages
RAR, 7-zip and other archive formats
What is WinMerge?
WinMerge is an Open Source differencing and merging tool for Windows. WinMerge can compare both folders and files, presenting differences in a visual text format that is easy to understand and handle.