fmWebFont

This mode sets the application to use Web Fonts. WebFMX automatically maps some not supported fonts and you are able to map others, by calling the method RegisterWebFont for each one of them.

fmBitmap

This mode will send each letter as a small png image and will store them into the web browser cache. This will ensure maximum fidelity, but it can be sometimes a little slower than the WebFonts mode.

fmAuto

On this mode, WebFMX will use WebFont or Bitmap based on the result of the OnSupportsWebFont event.

Inside the event you should indicate the environments where the WebFonts should be enabled and the other ones where WebFMX should work with the Bitmaps mode.