Actually if you read http://www.rockpapershotgun.com/2011/01/20/proto-minecraft-a... apparently releasing code (unintentionally) is what destroyed Minecraft's inspiration Infiniminer.

Why has this been downvoted? The game is free software, yet the (temporary) homepage has no link to the sources.

This is a most relevant question in a "Hacker News" site.

I haven't heard any mention of this game being free or open source. The software it uses (Voxlap & GenLand) both have permissive non-commercial licenses w/ attribution but are not viral like the GPL.

I stand corrected. I thought I'd read somewhere that it was free software. Maybe I misread "freeware" in TFA.