runs-on.dev
A free subdomain registry: claim yourname.runs-on.dev with a GitHub account, and the claim itself is one git commit to a public repository.
What it is
runs-on.dev gives away subdomains under a domain Advance Labs registered and is responsible for. There is no hidden database: the registry is a directory of JSON files, the history is the git log, and the rules CI checks on every pull request are readable in lib/. A wildcard *.runs-on.dev DNS record points every possible subdomain at one Vercel project, so claiming a name is a git commit rather than a DNS write; pointing a name at your own hosting merges a record and a GitHub Actions workflow pushes it to Vercel's DNS API. Open source, AGPL-3.0.
Why we built it
A real top-level domain means an ICANN application; the 2026 round's evaluation fee alone is $227,000, before a registry exists to back it. That is not a plausible way to get a distinctive address for a side project. runs-on.dev gets the same feeling — an ending other than vercel.app or github.io — for the cost of one domain, by giving subdomains away and keeping the registry itself public and auditable. It follows prior art (is-a.dev, js.org, eu.org) rather than inventing a new trust model.
What it proves
That we ship developer infrastructure we would use ourselves — Ninebrains' own public site runs on a claimed name (ninebrains.runs-on.dev), and the first project anyone else built on it (Overlap, a timezone scheduler) resolved with a valid certificate before any DNS was configured for it specifically. Saying plainly what the registry is, instead of dressing it up as a TLD, is the trust model, not a caveat on it.