tmux is a "terminal multiplexer". It allows a
number of terminals (or windows) to be accessed
and controlled from a single terminal. It is
intended to be a simple, modern, BSD-licensed
alternative to programs such as GNU screen.
Keyplex is a keyboard multiplexer for X11
terminals. It will spawn a number of terminals,
and when it has focus it relays all keystrokes and
mouse button 2 (paste) to them.
CGTerm is a set of telnet and chat clients that emulate the
PETSCII display of Commodore's 8-bit computers, with
colours and the correct font.
A static HTTP file server.
A tool that makes it easier to resolve TCP/IP connection errors.