knotsinside.me is a public XMPP server. Anyone can register, and it's completely free; however, you can donate Monero to the operator to help support this service.
If you use the service, I ask that you follow these few simple rules:
knotsinside.me uses XEP-0077 In-Band Registration. You can create an account on knotsinside.me from your XMPP client.