One App, Three Editions
In the past, DEVONthink for Mac was provided in three editions. Each edition had its own separate download on our website. With DEVONthink 3, we have created a single application with unlockable features, hence a single, simple download.
When you purchase a license for DEVONthink 3, it unlocks the features available under that license. For example, entering your Pro edition license in DEVONthink 3 > License enables the View > Import command for scanning and email archiving. Commands and items available higher edition are shown with a blue star ★ next to them. Selecting one of those items will open the License dialog and allow you to explore upgrade pricing, if desired.
If you are wondering what edition you're running, it is reported in the Registered to line in DEVONthink 3 > About DEVONthink 3. It is also shown when you press the Welcome link at the bottom of the Help > Support Assistant.