A proof-of-concept plugin sharing site is available at codedraken.github.io/ES-Mod-Share.

Instructions for creating plugins are on the wiki.

Eventually, it will be possible to download and install plugins from within the game. To support both that and a more detailed plugin listing here on the website, each plugin will need to provide, at minimum:

The preferred way to host a plugin is to create a GitHub repository for it. The "gh-pages" branch of the repository should contain the cover image and screenshots, and may also host a web page providing more information about the plugin. The "master" branch should contain the plugin itself. New downloads can be created just by tagging a release in the master branch.