The Ura-Zelda (literally, "Another Zelda") project was to be the first
The Legend of Zelda flagship
video game for
Nintendo's
Nintendo 64 addon, the
64DD. The idea behind the project was to release an
expansion pack for the hit game
The Legend of Zelda: Ocarina of Time that would add new levels, items, and characters and moved locations of existing items and enemies (but would not include
online play) for those players who already own
OoT, much like a "second quest", plus there was speculation that the game would have had an option to use the
64DD's
internal clock to map the day/night cycle to a normal clock and would have introduced the concept of seasons to the game.. The project was completed in 2000, however it was shelved after the
64DD met a horrible fate in the hands of the market.
Nintendo has never been one to develop a concept to completion and then leave it to gather dust forever, so in February 2003 the company released the game at long last (minus internal clock tricks and seasons) for the Nintendo GameCube as The Legend of Zelda: Ocarina of Time: Master Quest as part of a preorder bonus for those who ordered the new Zelda title, The Legend of Zelda: The Wind Waker.
References:
http://ign64.ign.com/articles/084/084100p1.html
http://216.239.39.100/search?q=cache:zIYZnuSmBH0C:www.legendofzelda.com/uranews1.html+ura-zelda+64dd&hl=en&ie=UTF-8