FL Studio has a native plugin called . Simply drag and drop the Z-Doc file into the player, and you are ready to record. (Note: If you are on a 64-bit version of FL, you may need to use DirectWave or a third-party bridge). For Ableton, Logic, or Cubase:

In an era where you can download the free "The Experience" piano from pianobook (which is 10GB), why would anyone use a 25MB Soundfont?

A quick search for "Z-Doc piano sf2" will lead you to a dusty Dropbox link or a piano chamber forum post from 2008. Download it. Load it into Sforzando or the free VST "Juice."