On January 9, 2009, Satoshi Nakamoto announced the first public release of Bitcoin, version 0.1, with binaries hosted on SourceForge. The announcement was made to the Cryptography Mailing List with the subject “Bitcoin v0.1 released.”
This was a Windows-only release, written in C++ with open source code included. The software allowed users to:
- Connect to the Bitcoin peer-to-peer network automatically
- Generate coins by contributing CPU power to the network
- Send and receive bitcoin transactions
- View transaction history
From the release announcement:
“Announcing the first release of Bitcoin, a new electronic cash system that uses a peer-to-peer network to prevent double-spending. It’s completely decentralized with no server or central authority.”
Satoshi described the proof-of-work difficulty as “ridiculously easy to start with,” noting that a typical PC could generate coins in just a few hours. The total circulation was set at 21 million coins, gradually released to network nodes based on CPU power contributed.
Block 1 was mined on the same day, marking the true beginning of the Bitcoin network’s continuous operation. Hal Finney was among the very first to download and run the software, famously tweeting “Running bitcoin” on January 11, 2009, and receiving the first known Bitcoin transaction (10 BTC from Satoshi) on January 12.