If you are creating Xojo desktop apps for your Raspberry Pi (and why not since Xojo Pi if free for desktop & console apps), you may want to take advantage of the HTMLViewer control for easy display of HTML content or apps.
By default, Raspbian does not include the necessary library to allow the HTMLViewer to work, but you can easily install it. Open a Terminal window on the Pi and enter this command:
sudo apt-get install libwebkitgtk-1.0.0
This will download and install the library needed by HTMLViewer.