Implementations
The software that speaks Bitcoin, and how its rules change.
- Bitcoin Core
The reference software most Bitcoin nodes run — descended from Satoshi's original code.
- Bitcoin Knots
A long-running variant of Bitcoin Core with stricter defaults and extra options.
- BIP 110
A proposed one-year rule change to squeeze file storage out of Bitcoin blocks.
- Bitcoin Core 30
The 2025 Core release that relaxed its data filter — and lit the spam war.
- Alternative implementations
Other software that speaks Bitcoin — useful, risky, and deliberately rare.
- BIPs
Bitcoin Improvement Proposals: how changes get written down, argued over, and adopted.
- Soft fork
A rule tightening that old software accepts — Bitcoin's way of upgrading without splitting.
- Hard fork
A rule change old software rejects — upgrade everyone, or the network splits in two.
- btcd
- Libbitcoin
- SegWit
- Taproot