TIL Darksend, InstantX, and Sporks are not unique to DARK, just broken copies of things BTC already does:
It's easy to bander the term "unique" around until you sit down and think about it:
- Darksend: a poor implementation of CoinJoin. To quote the actual inventor of CoinJoin (gmaxwell) on the topic of Darkcoin: "That other stuff was initially "hey this coinjoin stuff is great, we put it in an altcoin!" to which my result was "hey, idiots, the whole point of coinjoin was that it already worked in bitcoin. If you're talking about something incompatible there are much better approaches" ... and they've since gone off to do other things, but uh.. seemingly without a lot of thought in advance."
- InstantX: a clone of the GreenAddress instant Bitcoin transaction system, or more accurately a clone of Natanael L's "Secure zero-confirmation payments using temporary notarized P2SH multi signature wallets".
- Sporks: turns the Bitcoin alert key system into a remote kill switch that one person can use to disrupt the network at will. Awesome.