This web site has an XMPP instant messaging server.
I set it up so that my friends and I can enjoy encrypted groupchat.
My account is
Account creation is open.
Feel free to use this server to communicate securely with your friends and family.
I reserve the right to cut off accounts that abuse this service.
After deleting thousands of spam accounts,
I have suspended account registration
until I find a good reverse turing test
that isn't owned by google.
In the meanwhile, you can register an account on another public server,
ask me IRL to make an account for you on my server,
or set up you server.
There are many programs that will work with my server,
but here are some that support encrypted groupchat:
Android: conversations (free on f-droid), atalk, and zom
Iphone: chatsecure, monal, and zom
Windows: miranda and gajim
Here is a nice guide on setting up gajim, conversations, and chatsecure.