Previously, a crowd-sourced DApps listing was maintained here as part of the Moonbeam docs site. That registry is deprecated and replaced by State of the DApps. To list your project / DApp, check out this guide on the Moonbeam Docs Site that will walk you through the process of submitting your project/DApp to State of the DApps.
Disclaimer: State of the DApps contains user-generated content. You should verify any information with your own research. Moonbeam is a permissionless network. Any project can deploy its contracts to Moonbeam.
Submissions are typically reviewed by the State of the DApps team in one business day. For any Moonbeam-related questions you can reach out to us in Discord. For State of the DApps support, you can contact support@stateofthedapps.com