I am seeking a way to tag files and, if possible, folders or groups of files. I also wish to be able to search the files using these tags. With Windows 7 the search and tagging functions are available but the XMP standard is attractive; for the management of a large amount of geospatial data in a variety of formats, requiring storage in a deeply hierarchical structure, XMP-tagging (either by embedding or through an associated XMP file) may be a good choice going forward.
Wikipedia has a comparison of metadata editors http://en.wikipedia.org/wiki/Comparison_of_metadata_editors
but I have not found a 'XMP metadata search' function in any software. Does this exist? Is XMP a viable solution?