I spent quite a bit of time and effort on Zcoin during the launch, including setting up the first block explorer and mining with hundreds of EC2 instances to the point where I possessed more than 30% of the money supply.

It was a disaster. Some founders started selling their Zcoin as soon as it was listed on an exchange. The mining algorithm was changed several times.

It's a shame. Zerocoin, the underlying technology, is interesting.