Domain selection for developer tools and OSS projects carries a unique cultural context. Engineers understand the technical implications of TLDs, reading signals that general consumers would miss.

.dev — The new-generation standard — Google-managed with mandatory HTTPS (HSTS preloaded). Google’s own usage — web.dev, flutter.dev, github.dev — underscores its credibility. The most natural choice for developer tool landing pages.

.io — Tradition and tension — socket.io, itch.io, github.io (Pages) — a TLD that grew alongside startup culture. The “Input/Output” association resonates deeply with engineers. But the Chagos Islands sovereignty transfer risk materializes further each year. New projects should adopt .io with caution. Existing .io projects should have a domain migration plan.

.sh — Terminal dwellers — Saint Helena’s ccTLD, but the match with shell script file extensions (.sh) gives it a unique appeal among developers. deno.sh, railway.sh, warp.sh, charm.sh — the affinity with CLI tools and infrastructure projects is outstanding. However, general public recognition is extremely low.

.org — The heart of OSS — python.org, mozilla.org, apache.org, kernel.org — the history of open source is inscribed in .org. For community-driven projects, foundations, and standards bodies, .org declares “public good over profit.” Not suited for commercial tools, but the optimal choice for OSS.

.app — Application distribution — For official sites of mobile and desktop applications. bsky.app, poe.app, craft.app — suited for projects that have a “finished product as an app.”

A selection matrix:

Project Type	First Choice	Second Choice
Developer SaaS	.dev	.io (with risk awareness)
OSS library/framework	.dev	.org (if foundation-backed)
CLI tools	.sh	.dev
OSS foundation/community	.org	—
Finished application	.app	.dev

In developer communities, a domain is the address at the top of the README and the official URL in the npm homepage field. Choosing a technically appropriate TLD becomes part of a project’s character.