WinMerge is a visual text comparison application, that allows you to see the highlighted differences between 2 text based files. It is in particular useful for comparing source codes, and offers optional support for Visual SourceSafe syntax highlighting, customizable highlight colors and more. The program allows you to go through all found differences and then merge each instance by either replacing them on the right or the left side.
WinMerge is a Windows tool for visual difference display and merging, for both files and directories. Unicode support. Flexible syntax coloring editor. Windows Shell integration. Regexp filtering. Side-by-side line diff and highlights diffs inside lines.

WinMerge Features:
1. Visual differencing and merging of text files
2. Flexible editor with syntax highlighting
3. Handles DOS, UNIX and MAC text file formats
4. Unicode support
5. Difference pane shows current difference in two vertical panes
6. Location pane shows map of files compared
7. In-line word difference visualisation
8. File filters in directory diff
9. Moved lines detection in file compare
10. Shell Integration
11. Rudimentary Visual SourceSafe and Rational ClearCase integration
12. Archive file support using 7-zip

The license of this software is Freeware, you can free download and free use this file compare software.