1. Fast remote command execution over rsh/ssh/lsh The problem: logging in to a remote system with a cryptographic solution such as lsh or ssh takes time, due to the computationally expensive key exchanges that occur when the connection is established. It is common to trigger a lot of remote logins while using remote CVS, which makes it painfully slow compared to having the repository locally. The solution: reuse the secure tunnel once it has been established. fsh is a drop-in rsh-compatible replacement for ssh that automatically reuses ssh tunnels. From Debian 3.0r0 APT