In the past it was possible to login with Twitter and Facebook instead of your username/password. Over time this authentication broke because it required more encryption than this site supported.
Recently I updated the site from http to https and along with that comes a new slew of authentication options.
You're now able to either use Facebook, Twitter, Google, and/or Discord. If you already have an account on this site with the same email address as one of these services you'll be asked to authenticate to your current user account instead of creating a new one.