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.

• btcd

  A full-node implementation of Bitcoin written in Go, built for developers.

• Libbitcoin

  A C++ toolkit that rebuilds Bitcoin as libraries you can assemble yourself.

• 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.

• SegWit

  The 2017 upgrade that fixed transaction tampering and quietly raised block capacity.

• Taproot

  The 2021 upgrade making complex Bitcoin spends look — and cost — like simple ones.