Proof of concept clone of tmuxinator functionality based on iTerm and AppleScript instead.

sample_config.applescript

#!/usr/bin/osascript
set homePath to POSIX path of (path to home folder)
set iTermAutomation to load script POSIX file (homePath & "tmuxinator.scpt")

set projectDir to homePath & "Desktop/Ruby/growth-republic/iview-prototype"

tell iTermAutomation
  openFullScreenTerminal()
  activateSessionAndRunCommand("git fetch")
  splitPaneHorizontally()
  activateSessionAndRunCommand("bin/rails c")
  splitPaneVertically()
  activateSessionAndRunCommand("redis")
  splitPaneVertically()
  activateSessionAndRunCommand("bundle exec sidekiq")
  splitPaneVertically()
  activateSessionAndRunCommand("bin/rails s")
end tell

tmuxinator.applescript

global projectDir

-- http://www.iterm2.com/#/section/documentation/scripting

on activateSessionAndRunCommand(cmd)
	tell application "iTerm"
		tell the last terminal
			activate current session
			
			tell current session
				write text my goToProjectDir()
				write text cmd
			end tell
		end tell
	end tell
end activateSessionAndRunCommand

on splitPaneHorizontally()
	tell application "iTerm"
		tell the last terminal
			tell i term application "System Events" to keystroke "d" using command down
		end tell
	end tell
end splitPaneHorizontally

on splitPaneVertically()
	tell application "iTerm"
		tell the last terminal
			tell i term application "System Events" to keystroke "D" using command down
		end tell
	end tell
end splitPaneVertically

on openFullScreenTerminal()
	tell application "iTerm"
		activate
		
		tell i term application "System Events"
			-- new terminal with session
			keystroke "n" using command down
			delay 1.0
			-- fullscreen
			keystroke return using command down
			delay 3.0
		end tell
	end tell
end openFullScreenTerminal

on goToProjectDir()
	return "cd " & projectDir
end goToProjectDir

I implemented this in JS which is new in Yosemite if anyone is curious: https://gist.github.com/pmdarrow/96eb5fcc9c460336fc56.

This is very cool. I wish I had found it a few weeks ago. I just released iTermocil which is a command line tool for iTerm which allows you to easily configure sets of panes and commands:

https://github.com/TomAnthony/itermocil

I am a teamocil user, rather that tmuxinator, so iTermocil is compatible with teamocil files.