A Seamless X11 Experience on OS X

Up until Mountain Lion, Apple used to include a native X11.app in OS X, which - as you may have guessed - allowed users to run their X11 applications. With its removal, users turned to XQuartz to fill the gap.

I don't feel I need to touch on this much. You can simply go to the official XQuartz site, download, and install as you would most other software on OS X.

Let's say you're on a BSD or Linux distro: you want to install a new window manager or desktop environment. You'd usually just do that through the package manager, right? Well, same approach with OS X really, unless you're more comfortable building from source.

So, of course, I'm going to recommend Save OS X, but you could use any other package/ports managers available to get your actual X11 applications.

When using Save OS X this would be as simple as something like sudo pkgin -y in twm, then setting up your ~/.xinitrc as you would on any other system: echo "exec twm" > ~/.xinitrc, for example.

This next one depends how you'd like to interact with X11 and the extent of functionality that you desire.

When using XQuartz, you can opt to use a setting called 'Full-screen mode', found in XQuartz's preferences, under the 'Output' tab. This will, as one might be able to surmise, make XQuartz full screen. That is to say, the X11 server will occupy your entire display. Use of this option is as close to a 'standard' X11 set up as you can get. It allows you to use root-menus, Aqua's keybindings don't interfere, and you don't see any Aqua interface.

Whilst the above is nice, you may want to occupy your desktop with a mix of X11 & Aqua windows simultaneously. In doing so, you may be such a perfectionist that you don't want to see the dock or menubar - that was the case for me at least. You can do some trickery with Aqua applications' Info.plist to make certain UI elements behave a particular way.

To hide the dock and menubar when using an Aqua application, you can add the following properties to its Info.plist (usually located at /Applications/AppName.app/Contents/Info.plist):

<key>LSUIPresentationMode</key> 
<integer>4</integer>

This won't always work and its placement can vary. Simply replacing XQuart'z Info.plist with this one should achieve the desired behavior.

If you're heavily reliant on X11, and plan to use it a lot, you can have it auto-start using a launchd service.

Place something like the following in ~/Library/LaunchAgents/org.saveosx.startx.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>EnvironmentVariables</key>
  <dict>
    <key>LANG</key>
    <string>en_US.UTF-8</string>
    <key>LC_ALL</key>
    <string>en_US.UTF-8</string>
    <key>PATH</key>
    <string>/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin:/usr/pkg/bin:/usr/pkg/sbin</string>
  </dict>
  <key>Label</key>
  <string>org.saveosx.startx</string>
  <key>Program</key>
  <string>/opt/X11/bin/startx</string>
  <key>RunAtLoad</key>
  <true/>
  <key>StandardErrorPath</key>
  <string>/var/log/saveosx.log</string>
  <key>StandardOutPath</key>
  <string>/var/log/saveosx.log</string>
</dict>
</plist>

It should be quite clear from the above what's happening here. It's just like any other service management manifest, but uses XML to define keys and their values - just like SMF.

Once the above is in place, you can import the service and have it set to launch upon login by issuing the following command launchctl load -w ~/Library/LaunchAgents/org.saveosx.startx.plist

One problem with going the non-Full-screen path is that getting XQuartz to focus upon first launch can be quite a pain. I tackled this by simply having an instance of urxvt launch along with my window manager. If you use a panel/bar, this isn't as much of an issue, since your WM/DE has already launched an X11 tool which you can simply click on to gain X11 focus. However, if you're using a lightweight window manager, without any panel/bar - as there is the absence of a root-window (selecting the desktop will just focus Finder) - it can be quite awkward. Simply having a terminal, or something else in X11, launch automatically circumvents this issue.

Of course, if you opt to use 'Full-screen', you needn't worry about this.

Say you want to launch an Aqua application from dmenu, or you need to send a URL to Safari from urxvt. This is where the open(1) utility comes in handy. If you wanted to be able to open Safari using dmenu you could simply add a little shell script somewhere in your PATH containing the following:

#! /bin/bash
open -a Safari

Or if you're using the urxvt-perls perl extensions for urxvt and you need to tell it what to launch URLs with:

Urxvt-url-select.launcher:  open -a safari

Which reminds me, the following can be used with urxvt-perls for clipboard management:

URxvt*perl-lib:             /usr/pkg/lib/urxvt/perl/
URxvt*perl-ext-common:      default,clipboard
URxvt*keysym.M-c:           perl📋copy
URxvt*keysym.M-v:           perl📋paste
URxvt*clipboard.copycmd:    pbcopy
URxvt*clipboard.pastecmd:   pbpaste

This is all dead simple, but makes it a much more enjoyable experience. I didn't delve too far into integrating the two "sides", but I'm sure you could do some pretty nifty stuff with Automater/AppleScript.