.hack//Info Center
News, screen captures, timeline, character profiles, song lyrics, wallpaper, and forum.
.hack//SIGN
Official site by Bandai Entertainment. Story overview, production credits, video releases, trailer, and wallpaper.
.hack//SIGN Defragmented
Character and location profiles, episode summaries, and song lyrics.
.hack//UNIVERSE
Information on all three series', timeline, glossary, and MP3 downloads.
Dot Hackers
Storylines, character guides, and images from each part of Project .hack. Also includes timeline, multimedia, and message board.
I Go Wild
Shrine to Mimiru, with character and relationship information, image gallery, song files, and fan listing.
Player Kill
Shrine to Sora, with profile, screen captures, fan art, music, and oekaki board.
Yahoo! Groups: dot-hack-SIGN
Discussions of the anime series, with archives, songs, and image galleries available to members only.