A slide gun is a gun that fires gliders or other spaceships sideways from an extending arm. The arm consists of a salvo of spaceships which are continually pushing a still life or small constellation, releasing a glider in the process. This releases a wave of spaceships rather than a stream, as each spaceship is on a different path. The first slide gun was constructed by Dietrich Leithner in July 1994, and was based on a diagonal block-pushing reaction.
A tethered rake is similar to a slide gun in that it has an extending arm, but the end of the arm is in constant motion. This may mean that it has a spaceship or a volatile reaction at its front. Due to the precise timing of gliders or other spaceships required to support such reactions, tethered rakes are often more period-dependent than slide guns.