Chess World Champions: Mikhail Botvinnik - Features a biography and game playable through a java applet. - http://www.chesscorner.com/worldchamps/botvinnik/botvinnik.htm
Fide Title Tournament 1948: Botvinnik - Features downloadable .PGN Games, crosstable, and key game positions of 5-player tournament (Smyslov, Reshevsky, Keres, Euwe) held after Alekhine died holding title. - http://www.mark-weeks.com/chess/48$c$wix.htm