# Software Components ### XPI The CAM-XPI 19.xx.xx application includes support for Engage (VOS2) and UX (VOS) devices. The XPI 19.xx.xx and 20.xx applications are built off of the XPI 12.xx application code base which was used with the VX devices, but is packaged in a similar format to the XPI 5x00 application files used with the MX devices. {% hint style="info" %} NOTE: There is no XPI 19.xx.xx or 20.xx application for MX or VX devices. All VX devices will remain on the XPI 12.xx or 13.10 branch and all MX devices will continue on the XPI 5x00 branch. {% endhint %} ### Forms Processor (FP) The Forms Processor application replaces the Form Agent (FA) application which is used with the MX 9xx, XPI 5x00 applications. Unlike the FA application, FP application is not a separately released executable file, this is paired with the CAM-XPI application. The FP application is supported for Engage devices, although devices other than M400 and M440 will only have limited forms support. ### ADK The ADK is used by CAM-XPI and FP which allows a common interface to lower level functions of the operating system. The operating system is included as part of the ADK package. The ADK provides device “updaters” which allows the ADK components to be updated as opposed to replaced. ### Verifone Operating System **VOS/VOS2** - The Verifone Operating System (VOS/VOS2) controls the components on the Verifone devices, such as the user interface, hardware ports, display, keypad, and card processing. It is the software that speaks to the lower-level hardware components. The operating system is loaded on the PIN Pad at manufacturing. Application release notes will reference the VOS/VOS2 version since there can be a dependency on a feature implemented in a specific version. **VOS3 -** --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.verifone.com/xpi/tbd-documentation/xpi-migration-guide/software-components.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.