Meld is an open source tool used to compare files, directories and version controlled projects.
Meld is the visual diff and merge tool built for the developers. It is used for comparing two or three files or directories visually. It also compares the version controlled repositories. The differences are color-coded on different lines. Meld is supported by several popular version control systems such as Git, Mercurial, Baazar, CVS and Subversion.