paramikojs is a javascript port of paramiko. It powers the fireftp and firessh projects. However, some caution should be taken if reusing the code as not all code paths have been tested (in python, yes, but not in the translated javascript). So, coder beware!
paramikojs doesn't work out of the box. You should check out the fireftp or firessh projects for working examples on how to get something working. In particular, look at ssh2.js as a basic start to see how it glues together.
Before you ask, no this doesn't work on regular web pages. Being able to make an SSH connection only works currently in the context of a Firefox add-on which gives provides extra libraries/permissions (i.e. ahem, sockets)