A greeting or farewell said in the period between 12:00 AM (midnight) until 5:59 AM, known as postmidnight, wee hours, small hours, wee small hours, early hours, overnight, zero-dark-hundred, oh-dark-hundred, zero-dark-thirty or oh-dark-thirty.
n. software that is no longer sold or supported by the original publisher / developer, often found as free downloads on the internet because it cannot be obtained elsewhere. Not legal, but often seen as morally acceptable because the company that made it is no longer selling the title, nor releasing it as freeware, therefore abandonware is "keeping the gamealive", so to speak.
Doom II is not abandonware because idstill sells it, while The Incredible Machine is not sold, therefore is abandonware.