If you have an Obscure account, and you want to use the command line tools offered by our Linux server, you need to login using one of several available methods.
There are many ways to login to the server -- any telnet or SSH client will work. Telnet is an old protocol, available just about everywhere, but it is not secure. SSH is a newer, encrypted login protocol.
Set up your SSH client to connect to shell.obscure.org.
If you can't install software on the computer you are on, you can try to use one of these Java clients to login:
SSHTerm is full-featured, but it requires a 1.4-compatible JVM to be integrated with your browser.
Mindterm will work with just about any JVM, but it lacks some significant features (such as working cut-and-paste).