Lunar Lander is a name shared by several video games. In all variations of the game, the player must apportion a limited amount of fuel in order to land on the moon without crashing.
Lunar Lander started as a text-based computer game and went by the names Rocket, Lunar, LEM, and Apollo. Lunar was originally written in the FOCAL programming language for the Digital Equipment Corporation (DEC) PDP-8 computer by Jim Storer while a student at Lexington High School (Massachusetts) in the fall of 1969. A somewhat different version called Rocket was written in BASIC by Eric Peters at DEC, and a third version, LEM, also in BASIC was written by William Labaree II of Alexandria, Virginia. David H. Ahl converted Jim Storer's FOCAL version to BASIC, changed some of the dialog, published it in the EDU newsletter and distributed it through DEC's Education Product Group, which he headed at the time. A year or so later, all three BASIC versions first appeared under the names ROCKET (Storer version), ROCKT1 (Peters version), and ROCKT2 (Labaree version) in Ahl's book, 101 Basic Computer Games published by DEC in 1973. Ahl and Steve North converted all three versions to Microsoft BASIC, changed the name to Lunar Lander, and published them in Creative Computing magazine in 1976. They also appeared in an updated version of Ahl's games book simply called BASIC Computer Games published in 1978 which was re-published in 2010.
A text-only version of Lunar Lander, written in BASIC, was included with the eight-inch floppy operating system diskettes for the Datapoint 2200 series in the early 1980s. Playing it required three separate loadings: first the operating system, then BASIC, and then the program itself.
Source: Wikipedia, "Lunar Lander (video game)", available under the CC-BY-SA License.