Is there an exhaustive list of plugins for Dovecot?

**Background** I am looking for plugins for Dovecot (specifically authentication plugins) because I would like to look at source code for reference as to how to make an authentication plugin for Dovecot. I have search through the official list on the Dovecot website as well as a Google search for a list of plugins available. Unfortunately I haven't been able to find anything that fits what I am looking for. **Questions** Are there more plugins available than in the official list? Where can I find these plugins? Are there any authentication plugins available for Dovecot? I am looking for a response that answers all of the questions above. Thank you for your assistance.