You’ve tested it thoroughly, documented and wrote readmes, and chose a license. Congratulate yourself on this labour of love—but if you love something, set it free.
The most straightforward place to publish your mod is SpaceDock, a dedicated mod library for a few games, most notably Kerbal Space Program.
Submitting a new mod on SpaceDock is fairly straightforward—just make a new account, and head to the top-right menu to find the “create a new mod” button. Everything on this form is pretty straightforward.
SpaceDock integrates with CKAN and hence you can automatically send a request to have your shiny new mod listed on the archive network. Listing things on CKAN is actually still a manual affair, so it could take a day or two for it to appear.
After clicking on “create your mod”, your information and input will be saved but will not be made public, so take this time to just double check everything once more. Click on the publish button once you’re sure—once you publish a mod, you can’t de-list it without outright requesting its deletion.
From here on out you can also “edit this mod” if you want to change its metadata like titles and description, or “update this mod” if you want to upload a new .zip containing the latest iteration of your creation.
If you’ve been living under a rock, CKAN is the community-managed modloader that makes installing, checking compatibility, and dependency handling a breeze. Even if your mod’s not that complicated, many people find and browse for new mods on CKAN exclusively, elevating the profile of your work further. Good CKAN integration also just means less headaches dealing with people who installed your mod or its dependencies poorly, or neglect to check for conflicts.
If you uploaded to SpaceDock as per above and ticked the request above, a listing request will already have been sent. Nonetheless, it will still be useful to include specifics regarding links (like your mod forum thread or a manual) or mod compatibilities.
The tool is necessary if you’re not hosting your mod on SpaceDock, such as on GitHub or if you are just providing a plain HTTPS URL.
The simplest way to do this is to use the CKAN metadata webtool. This is a form you fill out, then automatically generates a GitHub issue/request with the relevant information. You will need a GitHub account, however, so get that sorted before continuing.
Some important fields are: