As an AI language model, I don't have information on specific products or software that are open source. However, I can provide you with some general information about touch screen kiosks and open source software.
A touch screen kiosk is a self-service interactive system that allows users to access information, services, or products through a touch screen interface. It can be used for various purposes, such as wayfinding, information display, ticketing, advertising, and more.
If you're looking for a 21.5 inch touch screen kiosk with a printer and LCD display, you may be able to find some open source software solutions that can be used with your kiosk. However, you may need to do some research to find the right software that fits your specific needs.
Some common open source software solutions for touch screen kiosks include:
1. Ubuntu Kiosk - a lightweight and customizable operating system that can be used for self-service kiosks.
2. Chrome Kiosk - a browser-based kiosk software that runs on Google Chrome and can be used for various kiosk applications.
3. Raspberry Pi Kiosk - a DIY kiosk solution that uses a Raspberry Pi computer and open source software to create a low-cost kiosk system.
Ultimately, the specific software you choose will depend on your requirements and the functionality you need for your touch screen kiosk. It's always recommended to do research and testing before implementing any software solution to ensure it meets your needs and works well with your hardware.