When doing software development projects, software code is an invaluable asset. Many teams prefer performing various kinds of code reviews. Redmine lets you share links with differences between source code among two commit versions with your team as simple as copying and pasting a URL where everyone can see the code. Luckily, these code review features are a built-in part of the repository module.
The repository module needs to be turned on and the repository added for a particular project you are going to view the code for. To learn how to do this, refer to the Getting ready part of the Using the issue-code relationship recipe from Chapter 3, Project Management with Redmine.