CDTree is an easy-to-use, efficient, and powerful media-cataloging tool. It will let you catalog and categorize CDs, CD-Rs, CD-RWs, hard disk directories, floppy disks, Zip drives, DVDs, and audio CDs for offline browsing. It also catalogs the contents of ZIP files and presents them in an intuitive way. The tool also can recognize if a CD has been scanned before and thus avoid duplication.