Pymux is a terminal multiplexer and a clone of tmux, but with some improvements, such as autocompletion menu as you can see below.

https://lh3.googleusercontent.com/-ZJVBn-JMjsQ/VpGbIiK3xOI/AAAAAAAAI4o/ZEfAn_67O88/s800-Ic42/pymux.gif

Panes have titlebar, which shows process command name, window title, also information from like using copy-mode. Using fish-style command-line suggestions, it also has 24-bit color support.

Pymux was created by Jonathan Slenders in 2014, written in Python 2/3 with Pyte, docopt, prompt_toolkit, and wcwidth under the New BSD License (3-clause), currently git-9877c9e (2016-01-09, v0.5 (2016-01-05)), works on Mac OS X and Linux.