Compare is described as 'Comparison plugin for Notepad++ editor' and is a Diff Tool in the Development category. There are more than 50 alternatives to Compare for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and BSD. The best alternative is WinMerge, which is both free and Open Source. Other great apps like Compare are Meld (Free, Open Source), Beyond Compare (Paid), KDiff3 (Free, Open Source) and Diffinity (Free).
Beyond Compare allows you to compare files and folders. By using simple, powerful commands you can focus on the differences you're interested in and ignore those you're not. You can then merge the changes, synchronize your files, and generate reports for your records.
Diffinity is a diff and merging tool with focus on accurate and easy to read source code diffs. It will compare the content of two files and present the differences in an easy to read line by line and char by char basis.
Merge is the visual file comparison (diff), merging and folder synchronization application from Araxis. Use it to compare and merge source code, web pages, XML and other text files with native application performance.
WinMerge 2011 series is a fork of the original WinMerge application that compiles without ATL/MFC dependencies to enable zero-budget developers to build WinMerge from sources using Visual C++ Express editions.