Apps to 3-Way Merge

TortoiseHg is a comprehensive graphical user interface (GUI) for the Mercurial distributed version control system. It provides a user-friendly way to manage your repositories, track changes, and collaborate with others, particularly well-integrated with the Windows File Explorer.

SmartGit is a powerful graphical Git client designed for developers across Windows, macOS, and Linux. It provides a visual interface to work with Git repositories, offering a comprehensive feature set for version control, code review, conflict resolution, and seamless integration with popular hosting platforms like GitHub and Bitbucket.

SourceTree is a free desktop Git and Mercurial client for Windows and macOS. It provides a graphical user interface for managing your repositories, simplifying complex version control operations and allowing both novice and experienced developers to visualize and interact with their code history effectively.

WinMerge is an open-source differencing and merging tool for Windows. It helps you compare, synchronize, and merge both files and folders, highlighting differences visually and providing robust tools for handling conflicts.