How large are these embroidery files? I feel like this is something that a SQL database might be able to help with. It's probably not an ideal solution, but remember that a filesystem is really nothing more than a database, which organizes files on-disk in a particular way and indexes them so that you can find them. It obviously has serious limitations due to its hierarchical nature, which is why relational databases were invented, so using existing tools it's probably quite feasible to create an application that uses a SQL database to index all the embroidery files and store all this data on them (license, whether it's a derivative of another one, and tags), and then if they're too large to just store in the DB itself, just point to files in the regular filesystem.