ReSharper 8.0 Web Help

A solution is not limited to sources included in your projects, but also contains references to libraries that are used in your solution. It is very convenient to have access and opportunity to navigate to source code of those libraries as if they are a part of your solution. ReSharper provides special functionality that helps you view and navigate through compiled code.

There are two types of navigation commands that target symbols in compiled code:

For the second type of commands, you can specify how ReSharper will represent external sources. When this kind of navigation is performed for the first time, you will see a dialog box, suggesting to choose the default navigation action:
You can also specify the default navigation action in the External Sources tab of the ReSharper options.