Compare two different files with this open-source tool
Meld allows you to compare two or three different files within one user interface. It can be used to compare pages of code to see where the patched code differs from the original code. You can even use it to compare two text documents to see where the same text has been duplicated in both documents. Set up a two-way or three-way comparison with this free tool.
Compare and merge your code
Meld allows you to compare two pieces of code, and if you wish, you may automatically merge them without having to go through the code manually. If you add elements within the user interface, such as by typing in new code, the tool will update the file comparisons as you enter each word. The tool visualizes what is duplicated and what is not. It uses different colors for duplicated and new content so you can see where one section differs from the other. The tool supports Git, Mercurial. Bazaar and Subversion. You may download the source code and the Windows app for free.
Should mostly be used by programmers
You can use it to compare text documents, but the tool requires a number of other programs already installed on your computer to the point where it is only worth your effort if you are a programmer comparing code. The auto-merge function that Meld offers is a big time saver, and the code is open source, so you may alter the tool to fit your own needs. If you are having difficultly installing it, they have a Wiki page and a help page to get you through it.