rubyterm

https://github.com/vidarh/rubyterm

rubyterm is a terminal emulator written entirely in Ruby. It cleanly separates a virtual screen buffer, an escape-sequence interpreter, damage-driven rendering, and swappable backends (X11, an ANSI/escape backend, and a headless bitmap rasteriser), so the terminal engine can be embedded in a Ruby application as well as run as a standalone X11 terminal via the `rubyterm` executable.