Malaniuk was renowned as a very good rapid player and theoretician who contributed greatly to the Dutch Leningrad defence.
He was three times champion of Ukraine and represented his country in three Olympiads 1994-1998, winning team silver in 1996 and team bronze in 1998.
In 2005 he was runner-up in the European Rapid Chess Championship and Keres Memorial in Tallinn.
Wikipedia entry
FIDE sends its highest condolences to his family and friends.