Pokémon Gold Version[a] and Pokémon Silver Version[b] are role-playing video games developed by Game Freak and published by Nintendo for the Game Boy and Game Boy Color. They are the first installments in the second generation of the Pokémon video game series. They were released in Japan in 1999, Australia and North America in 2000, and Europe in 2001. Pokémon Crystal, an enhanced version, was released roughly a year later in each region. In 2009, on the 10th anniversary of the games, Game Freak remade Gold and Silver for the Nintendo DS as Pokémon HeartGold and SoulSilver.