HAL FINNEY: “I was likely the first person after Satoshi to run Bitcoin. I mined block seventy-something and received the first BTC transfer when Satoshi sent me 10 coins as a test. We emailed for days after that, mostly me reporting bugs and him fixing them in real time, almost instantly.”

Hal Finney claims to be the first person after Satoshi to run Bitcoin, mined block seventy-something, and received the first BTC transfer of 10 coins from Satoshi as a test. He reported bugs to Satoshi, who fixed them in real time via email.