A PXX file is an encrypted customization file created by Keyman Developer, an application used to create, edit, and distribute digital keyboards for any type of language. It contains information about the user interface of a custom keyboard that was compiled from a .KCT customization source file.

After creating a custom digital keyboard, Keyman Developer enables you to distribute the keyboard to other users. The PXX file is included with the distribution of the keyboard and should not be distributed separately. By default, the PXX file is placed in the project output folder with the .MSI file after you compile the KCT customization source file. Also, the PXX file is locked to the product installer it was created with, which means you cannot use the PXX file with any other Keyman product.