DIGBT is the BitTorrent DHT search engine.
DHT is a protocol for searching nodes which distribute a torrent.
Torrent is a file with metadata which describes distributed content.
DIGBT is not a tracker and doesn't store any content and only collects torrent metadata (such as file names and file sizes) and a magnet link (torrent identifier). This means DIGBT is the entirely legal system.
In addition to legality, DIGBT has two important properties: unicity and decentralization. Unicity means that DIGBT is the first system of its kind and there is nothing analogues yet. Decentralization of DIGBT provides the opportunity to search in the entire "torrent" space inside and outside of trackers (except private trackers).