A railgun is a device that uses an electromagnetic field to launch a projectile. They range from large, fixed emplacements to smaller personal weapons and can launch rounds at extreme velocities. Large scale shipboard railguns, such as those on many dreadnoughts, are commonly referred to as mass drivers and can be used to propel cargo as well as projectiles and warheads, although this requires an arresting device (such as another mass driver) to “catch” the pitch.
A space elevator is another non-military application of the principle.