Self-hosting preparation

This is contributor documentation. To use Hydrogen, start with the released compiler in the Getting Started section.

The compiler parses Hydrogen source, binds names and types, lowers reachable methods into executable IR, and emits native x86-64 output. The current Linux backend includes its runtime in each executable; the UEFI path uses a deliberately small PE32+ image builder for the firmware console proof.

The compiler’s own CLI project is within the supported language subset, enabling a verified Hydrogen binary to rebuild that project closure without a C++ toolchain.

Features outside the released subset must not be assumed to work merely because older design material describes them. Extend the parser, checker, IR, backend, and tests together when adding language features.