A database? DEVONthink is more: it's a wide open file vacuum that allows for information to be stored, turned into hierarchies and then manipulated. It "associates" information, even sections of stored documents with other documents in the database. It's a thinking database. It recognizes words and terms and suggests associations... It creates links. Frankly, I'm not really doing it justice. The app gets richer over time, but it is necessary to fight through the documentation, which is not plain and assumes too much of the end user. As to the criticisms of UI, they're weak, tantamount to criticizing the Mars Landers for their lack of streamlining. The issue is functionality not appearances.

In this area, the best app I have ever run. Theoretically dedicated to the desktop productivity and organization (true) but, the more you use it, the more it fits to unexpected use cases. This tool has almost no limit but that of the imagination. Depending on needs, can be associated as well with the efficient and customizable Web search engine called DevonAgent.
The user interface is not very smart nor "modern", the learning curve is a bit long but I do encourage any newbie to be patient because this flexible, robust and reliable app is really worth seeing.

DT Pro is the best app ever. Its AI features are second to note. The only thing that I don't like is… hum… well… honestly there's nothing I don't like :)
I can't recommend it enough.
Oh yes, just one thing: the help is not translated, which may be a problem for some users.