Foundational papers, reproduced word for word, with interactive diagrams over the original text. Hover a term for a plain-language definition, or open an explainer you can actually run — mine a real block, tamper with a transaction and watch it break.
Satoshi Nakamoto
How to make cash work online without a bank in the middle. Digital signatures, proof-of-work, the longest chain, and the attacker math — the whole paper, verbatim.
Vitalik Buterin
From a single-purpose ledger to a programmable one: accounts, gas, the virtual machine, and contracts that run on the chain.