The class/package dependency diagram editor is the cornerstone of eDepend, it displays elements dependencies, relationships with libraries/other projects and dependency cycles.
Use the following ways to open a class dependency diagram:
Right click one element in Package Explorer and select eDepend -> Class dependence explorer in popup menu

Select the dependency kinds to display on diagram and click the Finish button

A class dependency diagram has been opened

Use the following ways to open a package dependency diagram:
Right click one package in Package Explorer and select eDepend -> Package dependencies explorer in popup menu

Select the dependency kinds to display on diagram and click the Finish button

A package dependency diagram has been opened
