Meld allows you to compare two or three different files in one user interface. It can be used to compare pages of code to see where the corrected code differs from the original code. You can even use it to compare two text documents to see where the same text is duplicated in both documents. Set up two-way or three-way comparisons with this free tool.

Meld allows you to compare two pieces of code, and if you want, you can automatically merge them without going through the code manually. If you add elements to the user interface, such as by entering new code, the tool will update file comparisons as each word is entered. The tool visualizes what is duplicated and what is not. It uses different colors for duplicate and new content so you can see where one section is different from another. The tool supports Git, Mercurial, Bazaar and Subversion. You can download the source code and application for Windows for free.

You can use Meld to compare text documents, but the tool requires a number of other programs already installed on your computer, to the point where your efforts will only be worth it if you’re the programmer comparing the code. The automatic merging feature that Meld offers is a huge time saver, and the code is open source so you can modify the tool to suit your needs. If you have difficulty installing it, they have a Wiki page and a help page to help you figure it out.