Delphi has been around for a long time, but XE4 is no different, comes with DUnit. You must make sure that you select it in the settings.
The version that ships with Delphi is already updated to work with the version of Delphi that comes with it. Looking at the DUnit sourceforge project, it looks pretty moderate. The last commit in the SVN archive, which mentions Delphi versions, refers to Delphi 2009. Therefore, it seems to me that it is best to stick with the version that comes with Delphi.
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