RHYTHMOLOGY

Guides

IIDX.org
Guides to IIDX

The Japari
articles translated from The Safari

Voltexes
Guides to SDVX

Tables

Stardust
Starlight
Satellite
Flora
Stella

SDVX Clearing Spreadsheet

Chart Viewers

Texatage
IIDX chart viewer

sdvx.in
SDVX chart viewer

popn.tools
Pop'n chart viewer and card draw

Wikis

Bemaniwiki
Detailed information on Bemani game systems/unlocks

Remywiki
Comprehensive song information for Bemani and Gekichumai

Namuwiki
Everything else you could possibly want to know