UNIX shell
One day, this page will be much longer, with a big list of all the fun things you can do with your shell account at doo.dad.
For now, here are the essentials:
Logging in with a web browser
You can access your shell account via the web, at shell.doo.dad.
Logging in with an SSH client
You can also access your shell account by using SSH to connect to boo.doo.dad, but only after you have uploaded an SSH public key. You can use Usermin to upload your key after you have generated it.