Semantic Technologies for different Operating Systems

I'm trying to write an application that categorizes a certain type of file, music for example, or pictures. As part of the application users would be able to tag items so as to make searching more efficient. These tags could be location and place of a picture, or it could be the camera it was taken with, or even the emotion that a person feels when looking at the picture.

I can foresee that this information would be very useful to the operating system for it's desktop wide searches. That way users would not have to open my application to search for content based on the tags they provide.

I'd开发者_JAVA百科 like to know what technologies are native to different operating systems/desktop environments. I know of (meta?)tracker for Gnome, and I'd be interested in hearing about equivalent for KDE, Windows and Mac OSX.

For KDE I can point out:

• digiKam for images management
• amaroK for music

I think they both do what you want. However, I'm not quite sure what is the scope of your question: are you just looking for existing tool for tagging/rating images/music?

Well, this question has been out for a while and I've done research since I asked this question, and here is what I've found.

For KDE there is a component called Strigi, which is required by plasma, and this provides the file tagging and search functionalities along with something called Nepomuk.

Gnome has tracker, which does the same thing, and seems to be a component of the Gnome desktop.

Windows has tagging, but I haven't found out how one can programmatically access the tags on the files, or how generic they are. However it is only possible to tag certain file types, so txt files for example can not be tagged.