Welcome to the public.me documentation site. 
public.me is a tool to publish Apple Reminders online. 
Why would you might want to need it?

You can create things like wishlists, daily habit tracker, list of books to read, list of trips to take. You can create those things on your Mac, iPhone, iPad. Share them online with your friends, family.

And you can make changes to those lists whenever you want - they will be automatically updated online.