Chris over at the EEVblog forum designed and built this DIY Metcal 13.56 MHz RF supply:
A while ago i came up with my own circuit for that, plus some nifty firmware (which basically is optional). You can see what i have done so far on the EEV-Blog forum here
As of recently the whole thing is working. I know that the Metcal system is more of a niche thing, but i think quite interesting none the less….
Via the contact form.