Love it for its features or despise it for its ubiquity, Microsoft Word is the standard for manuscripts in the publishing industry. Track changes is built into the application on both the Mac and PC versions. This screenshots here were taken on a Mac, but you can look up details for Windows on the Microsoft website.
Track Changes is an editing tool, and with it enabled, Word will display all of the alterations you you’ve made. You–and anyone else working on the file–can also accept or reject any changes. (Accepting a change also wipes out the history behind it. We’ll come back to this last point.)
Track Changes is also a collaboration tool, and as you can see in the above screenshot, it lets you leave notes for writers. They’re color coded, so comments left by different users can be identified quickly.
But sometimes things aren’t so neat: Some writers insist on taking any editorial changes and pasting them into their original document. Editors will get multiple versions of a file with different changes that may or may not have a change history associated with them. But don’t worry, Word has you covered there too: The Compare Documents feature will generate a new document and show you the differences.
You can turn Track Changes on and off in Word’s “ribbon”, in the Review tab. There are also buttons here that let you view the original, unchanged text of a document; that help you navigate through comments; and buttons to accept and reject changes–whether one change at a time or an entire document’s worth of edits. (Be careful with that last one.)
When everybody involved in a manuscript–author, beta readers, editor, agent, proofreader–knows how to do all of this, you’ll end up with a document that including everybody’s notes and changes, nicely color-coded. When you’ve been through a manuscript a few times already, this is a great time-saver. It also gives an author a high level of control over the final product.
Track Changes is mostly used for novels and business documents, but I also use it for blog posts when I’m working with writers who prefer several rounds of back-and-forth changes. OpenOffice has a similar set of features, but Word has implemented it in a way that’s much easier to use.