Asciinema : Asciinema is a free and open source solution for recording the terminal sessions and sharing them on the web.
terminal-copilot : With terminal-copilot, you can quickly and easily access commonly used terminal commands right from the command line. Simply type copilot followed by ...
tmate : Tmate is a fork of tmux. It provides an instant pairing / sharing solution for the terminal.
GateOne : Gate One is an HTML5-powered terminal emulator and SSH client
3mux is a terminal multiplexer with out-of-the-box support for search, mouse-controlled scrollback, and i3-like keybindings. Imagine tmux with a smaller learning curve and more sane defaults.