Keyclone is a key broadcasting application that allows users to control multiple instances of an application using a single keyboard/input device. While commonly used for multiboxing videogames (playing multiple characters at once), Keyclone is suited for a wide range of use cases that require broadcasting individual inputs to multiple instances of an application.
Essentially, keyclone is a program to program, unicasting keyboard emulator.
Keyclone links applications together...enabling you to hit 'F1' within one application, and having that key simultaneously sent to each of the other applications Keyclone is managing. it will also send those same keys to any other instances of Keyclone you may have linked in, which in turn will distribute the keys to the applications they are managing.