A KVK file contains an on-screen keyboard created by Keyman Developer, a program used to create, edit, and distribute digital keyboards. It stores information about a virtual keyboard, which includes the layout of characters assigned to keys, constraints, and dead keys.

The KVK file is created using the Keyboard Editor that comes with Keyman Developer. You can open it by selecting File → Open and selecting the KVK file type. The KVK file is used for compiling a keyboard for distribution to Keyman Desktop users. It is compiled along with a KMN and .ICO file. When compiling the KVK file into an Android, iOS, or web keyboard, the content in the KVK file is embedded into the output file. However, when compiling into a desktop keyboard for Windows or macOS, the KVK file is included with the keyboard file for distribution.