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.

WinMerge is highly useful for determining what has changed between project versions, and then merging changes between versions. WinMerge can be used as an external differencing/merging tool or as a standalone application.

Features

In addition, WinMerge has many helpful supporting features that make comparing, synchronising, and merging as easy and useful as possible:

General
- Supports Microsoft Windows 98/2000/XP/2003/Vista/2008
- Handles Windows, Unix and Mac text file formats
- Unicode support
- Tabbed interface
File Compare
- Visual differencing and merging of text files
- Flexible editor with syntax highlighting, line numbers and word-wrap
- Highlights differences inside lines
- Difference pane shows current difference in two vertical panes
- Location pane shows map of files compared
- Moved lines detection
Folder Compare
- Regular Expression based file filters allow excluding and including items
- Fast compare using file sizes and dates
- Compares one folder or includes all subfolders
- Can show folder compare results in a tree-style view
Version Control
- Creates patch files
- Resolve conflict files
- Rudimentary Visual SourceSafe and Rational ClearCase integration
Other
- Shell Integration (supports 64-bit Windows versions)
- Archive file support using 7-Zip
- Plugin support
- Localizable interface
- Online manual and installed HTML Help manual

File compare window is basically two files opened to editor into two horizontal panes. Editing allows user to easily do small changes without need to open files to other editor or development environment.

WinMerge allows selecting/opening paths in several ways. Using the Open-dialog is just one of them.

Folder compare shows all files and subfolders found from compared folders as list. Folder compare allows synchronising folders by copying and deleting files and subfolders. Folder compare view can be versatile customised.

In the tree view, folders are expandable and collapsible, containing files and subfolders. This is useful for an easier navigation in deeply nested directory structures. The tree view is available only in recursive compares.