Due to the increased number of requests for JS.ORG subdomains, with many having questionable relevancy to the JavaScript community and ecosystem, we've decided that going forward JS.ORG will be focusing on accepting subdomain requests from projects with a clear relation to the JavaScript community.
As some examples, personal pages, blogs, Discord bot pages and basic tutorials for unrelated libraries will no longer be accepted. Projects such as NPM packages, libraries, tools that have a clear and direct relation to JavaScript, will be accepted when requesting a JS.ORG subdomain.
This decision does not affect subdomains that have already been granted.
If your project does not meet the criteria of JS.ORG you should have a look at the list of similar services.
To get a short and sleek subdomain for your own GitHub Pages site from JS.ORG follow these 4 steps:
If you haven't already, log in to your GitHub account and set up your GitHub Pages site following their instructions. Make sure to add some reasonable content to your new page.
Now determine your JS.ORG subdomain: either choose your username or the name of your repository according to the existing GitHub Pages URL (for http://foo.github.io/bar, either foo.js.org or bar.js.org would be possible). More details are available in the wiki.
Add a file named CNAME to your repo (in the gh-pages branch for project pages, or the branch that you've set as your GitHub Pages source) with a single line matching the domain you have chosen (e.g. foo.js.org). If you prefer a web interface form, have a look at GitHub Pages Help.
To finish the procedure, make a pull request in this GitHub repository that adds your subdomain to the subdomains list of existing JS.ORG domains. Your new URL should go live within 24 hours (keep an eye on your pull request in case of a naming conflict or if there are requested changes).
Thanks to Cloudflare for their awesome DNS service that makes this service possible. While JS.ORG is using their free plan - to a shameless extent - they helped us more than once with some flexible solutions and extended quotas. Many thanks!