Counterparty is a platform to manage cryptographic assets. It extends bitcoin's functionality by writing in the margins of regular bitcoin transactions.
Counterparty did not hold a crowdsale or ICO, but did issue XCP, about six months after Omni in January 2014, to the bitcoin address 1CounterpartyXXXXXXXXXXXXXXXUWLpVr.
2130 bitcoins were received and then subsequently burned and destroyed using a technique called proof-of-burn to avoid pre-mining. The terms of the swap were that one bitcoin burnt would garner between 1000 and 1500 XCP, as stated by Counterparty on bitcointalk:
"No more than 1 BTC may ever be burned by any address, and the number of XCP received per BTC is between 1000 and 1500, with more XCP being rewarded the ...