The KEY file extension is used by various programs for licensing software. KEY file contains registration information or a security code for a software program. It is not meant to be opened by a single program as KEY files are used by various software products.
The KEY file extension is used for settings files that defines keyboard shortcuts or keyboard layouts for different languages. Keyboard definition formats are frequently used in computer games.
The KEY file extension is associated with iWork Keynote. Keynote is a presentation software application developed as a part of the iWork productivity suite by Apple Inc. Key files are basically ZIP archive that contains a the main presentation document, previews and some metadata.
The KEY file extension is associated with LightWave. LightWave is a 3D computer graphics software developed by NewTek. KEY files store license key and enable users to active the software.