Hydrogen Branch Map

main is the new version of Hydrogen. Classic Hydrogen lives on the 2026-04 back-fix branch. Both were developed in parallel from June to October 2026, so new vs classic Hydrogen diverged — details below.

Naming: never write "Hydrogen 3" or "Hydrogen 2" in public artifacts (docs, changelogs, PR descriptions, support replies). Externally they are "the new version of Hydrogen" and "classic Hydrogen" (also "legacy Hydrogen"). The README phrases them by version: "Hydrogen 2026-10 or later" and "Hydrogen 2026-04 and earlier"; public changelogs use neither phrase.

Where everything lives