You're new to the internet, aren't you? Duke Nukem 4, aka Duke Nukem Forever has been in production since WWII and has an expected release date of somewhere around the 25th century, just after the return of Jesus and just before England win another cricket match against Australia.
Funnily enough though, it's made a
reappearance in recent days, 10 years after it was first announced (scarily). I remember seeing screenshots for this around the end of 1997, looks a bit different now though. Hail to the king, baby.