I've used it a little bit; it's simple, effective and free. I'm not sure about the imperial to metric conversion though; I'll have to have a squiz at the code... oh, did I mention it's FOSS?

Thanks again, Palmer.A pound of LME typically yields a gravity of 1.034 - 38, as measured by a hydrometer, when dissolved in one gallon of water. DME yields about 1.040 - 43.