Endgame Tablebase
Databases containing perfect play solutions for positions with few pieces remaining.
CH
ChessTempo
Comprehensive chess training site renowned for its tactics trainer, opening trainer, and large game database.
SY
Syzygy Tablebases
Online interface to Syzygy endgame tablebases, giving perfect play information for all positions with up to 7 pieces.
EN
Endgame Trainer
Interactive endgame training site with positions from basic K+P endings to complex rook and queen endgames.