Some noob was using it. Being a long time falling sand user I asked him what it was. He told me it was Powder Toy. I think he's already forgotten about it, for all he did was blow crap up (Like most noobs)
A site that listed different freeware/open-source games and apps. It was sometime prior to heat simulation. I remember pressure used to be the bee's knees. Pressure view was like the fanciest view setting there was and there was no heat effect, everything was done by pressure. Around summer of '07.