RubyTerm is my xterm / rxvt replacement… It is incomplete. It is slow, but usable.

Most notably, it supports rendering both to X11, to text so that you can use it to run terminal applications in “windows”/panes in your terminal (think like tmux), or to a bitmap buffer, and you can also drive it from Ruby if you want to open an X11 window with a terminal attached under your control.

It uses a pure-Ruby font renderer, and a pure-Ruby X11 binding…