As noticed by several users running the developer preview version of OS X 10.8 Mountain Lion, Apple is no longer including its X11 application for running software through the X Window System interface. A popular option for scientists and others seeking to run specialized UNIX software both on local machines and across networks, X11 has been available on OS X for a number of years and has been included as a default install since Mac OS X Leopard.

x11 mountain lion alert
The X Window System has an extensive open source history, with development on the Mac side being handled under the XQuartz project. Apple's X11 application has been based on this effort, although as with many open source projects bundled for use in commercial software, X11 has generally been somewhat behind the latest XQuartz releases. The current version of X11 is 2.6.3, while XQuartz is currently available in version 2.7.0.

With Mountain Lion, Apple seems to eliminating its dedicated support for the X11 application, instead redirecting users to the open source XQuartz project, which it will continue to support.

Top Rated Comments

jeremyhu Avatar
180 months ago
THis is having an incredible negative effect upon programs in ML.

GIMP wont run even with Xquartz
It runs fine for tons of users. Are you experiencing a specific issue? If so please report a bug.


CrossOver does not launch Windows programs correctly, and instead shuts down
CrossOver ships their own server and does not actually use anything from Apple's X11 except for quartz-wm. I suggest you contact Codeweavers for access to test versions of Crossover that will work on Mountain Lion.


MacPorts is useless (Not just because of X11, but because of changes to Xcode)

Yeah, there are a few bugs to be worked out
As with most updates, MacPorts will need to adjust to this change. We're working on it, and you can follow the thread I started on macports-dev for specific information.

----------

This isn't just a removal, where reinstallation via XQuartz fixes things all nice and neat.
Please use the latest rc version of XQuartz (currently 2.7.1_rc4). As you probably discovered, earlier versions (like 2.7.0) don't fixup some things.


All the underlying launchd mechanisms that made the Apple X11 function so well with previous versions are gone as well. All the automatic $DISPLAY setting methods, for example, are ripped out. Installation of the XQuatrz package does nothing to fix that.
That's not true. XQuartz sets $DISPLAY for you (and always has). You need to logout and log back in to get $DISPLAY. This is mentioned on the download page and in the installer.

----------

Since there's no way to get the old startx methods to work anymore -- because they're just gone.
What do you mean? The entire startup sequence for XQuartz is based on xinit and startx. If you're having issues, please file bug reports with specific information.


This is not something they'll be fixing. I hope XQuartz manages to do something about it, but there are no guarantees. This is the kind of thing that can become orphanware in a hurry.
About what? File bugs, and they'll get fixed in time. I can't fix bugs I don't know about ;)

----------

Bingo! There was no point in Apple shipping it since we could get the latest version via open source. Only problem here is that Apple is no longer guaranteeing that X11 will work when a new version of the OS ships.
Note that All of X11 is based off of public APIs except for a small set of "private" APIs in a library that lives at /usr/lib/libXplugin.dylib ... as long as that library is updated for future releases, it should "just work"


Its possible for OS X to break X11 and the open source XQuartz team to have to quickly produce an update to support new operating system releases.
Yeah, but seeing as how the "open source XQuartz team" is 99% @apple.com, I think that's probably not difficult...


Its probably not much of a concern if you wait a couple weeks after the release of a new version of OS X to upgrade. They should have any required updates available to XQuartz within a few weeks (or possibly before) release of OS X, given the availability of developer previews.
Actually versions of XQuartz that work with Mountain Lion were released well in advance of Mountain Lion. You just need to be using the rc versions of XQuartz. 2.7.1_rc4 works great with it.

----------

Can someone confirm that Matlab works with XQuartz?
Yes.

----------

Make no mistake. XQuartz doesn't work in its present form on ML.

Don't know if I can make it plainer.
File bug reports.


Yep. Installed. Tested. Failed. Debugged. Failed. Next?
You installed the wrong version. Install 2.7.1_rc4.

----------

Is the fact that removing X11 causes various applications to break not a valid concern?
It is a valid concern. Please report problems.


I occasionally use GIMP, but according to various posters, it no longer works, even with XQuartz. Will you be buying me a similar photo editing application so I can work with my photos when 10.8 comes out?
No, but I will fix bugs if you report them. gimp runs fine here, but I'm by no means a gimp power user.
Score: 38 Votes (Like | Disagree)
theluggage Avatar
180 months ago
THis is having an incredible negative effect upon programs in ML.

Yeah. What they ought to do is release some sort of "Developer Preview" 5 or 6 months ahead of the release of the new OS so that developers heard about these things and had time to produce fixes.
Score: 33 Votes (Like | Disagree)
macduke Avatar
180 months ago
Is ML really an update? It seems like a downgrade in many respects.

Do you really know what you're talking about? It seems like you really don't know what you're talking about in many respects.
Score: 18 Votes (Like | Disagree)
godknows Avatar
180 months ago
Is ML really an update? It seems like a downgrade in many respects.

Stuff like this should really be optional. Not everyone uses it.
Score: 18 Votes (Like | Disagree)
KnightWRX Avatar
180 months ago
I guess this will be another "dumbing down" thread. :rolleyes:

Anyone who was using X11 on OS X (myself included) never really bothered with Apple's version anyhow and went straight to XQuartz.
Score: 17 Votes (Like | Disagree)
displaced Avatar
180 months ago
Too early to be worried...

So, the facts are:


* Xquartz is the open source X11-compatible window server for Mac OS X
* Xquartz is maintained by Apple-employed developers. It's an Apple-sponsored open source project.
* The 'X11' app bundled with various OS X releases has historically been a snapshot of the Xquartz code, renamed and integrated with the Mac OS X release.
* There was some extra 'glue' which made the Xquartz snapshot known as X11.app behave extra nice with OS X ($DISPLAY setting, etc)


So the actual change in Mountain Lion is that:


* Apple will no longer be bundling re-labelled Xquartz versions with OS X.
* OS X will instead prompt the user to download Xquartz when an X11-dependent application runs.


Now, clearly there's been a shift in responsibility here. The OS X team no longer take responsibility for integrating Xquartz (branded 'X11') into OS X major releases.

Rather, the Xquartz team (still Apple employees, remember) need to build up their process for producing releases independently of the OS X team. This is where the 'glue's got lost. Whatever OS X used to do for X11.app/Xquartz, Xquartz is now going to have to do for itself. From their point of view, it's almost certainly too early to start down that road since ML is still such a moving target. Hence the lack of integration in the present DP state.

I'm failing to see the malice, neglect or otherwise here. Rather, it's letting the Xquartz team control their schedule and deliver their updates independently of OS X without having to rely on people seeking out and installing Xquartz on their own.

Bear in mind also that the third-party developers will also take a little bit to adjust. They've been used to being able to test against 'the X11 that comes with <OSX_VERSION>. Instead, they'll need to test against the current release of Xquartz.

We're only about 24hrs into Mountain Lion's public history... so let's give everyone involved a chance to sort things out.
Score: 14 Votes (Like | Disagree)

Popular Stories

iPhone Pocket Short

iPhone Pocket is Now Completely Sold Out Worldwide

Tuesday November 25, 2025 7:16 am PST by
Apple recently teamed up with Japanese fashion brand ISSEY MIYAKE to create the iPhone Pocket, a limited-edition knitted accessory designed to carry an iPhone. However, it is now completely sold out in all countries where it was released. iPhone Pocket became available to order on Apple's online store starting Friday, November 14, in the United States, France, China, Italy, Japan, Singapore, ...
Netflix Smaller 4

Netflix Kills Casting From Its Mobile App to Most Modern TVs

Monday December 1, 2025 4:36 am PST by
Netflix has quietly removed the ability to cast content from its mobile apps to most modern TVs and streaming devices, including newer Chromecast models and the Google TV Streamer. The change was first spotted by users on Reddit and confirmed in an updated Netflix support page (via Android Authority), which now states that the streaming service no longer supports casting from mobile devices...
Cyber Week Deals 2025

Best Cyber Week Apple Deals Include Big Discounts on AirPods, Apple Watch, and More

Sunday November 30, 2025 7:33 am PST by
Cyber Week is here, and you can find popular Apple products like AirPods, iPad, Apple Watch, and more at all-time low prices. In this article, the majority of the discounts will be found on Amazon. Note: MacRumors is an affiliate partner with some of these vendors. When you click a link and make a purchase, we may receive a small payment, which helps us keep the site running. Specifically,...
Sad Siri Feature

Apple AI Chief John Giannandrea Retiring After Siri Delays

Monday December 1, 2025 2:16 pm PST by
Apple AI chief John Giannandrea is stepping down from his position and retiring in spring 2026, Apple announced today. Giannandrea will serve as an advisor between now and 2026, with former Microsoft AI researcher Amar Subramanya set to take over as vice president of AI. Subramanya will report to Apple engineering chief Craig Federighi, and will lead Apple Foundation Models, ML research, and ...
studio display purple february

M5 iPad Pro Could Hint at New Studio Display Feature

Sunday November 30, 2025 10:30 am PST by
The updated specs of the M5 iPad Pro may point toward a major new feature for Apple's next-generation Studio Display expected in early 2026. Apple's latest iPad Pro debuted last month and contains one display-related change that stands out: it can now drive external monitors at up to 120Hz with Adaptive Sync. The feature should deliver lower latency, smoother motion, and fewer visual...
iOS 26

When Will Apple Release iOS 26.2?

Monday December 1, 2025 4:37 pm PST by
We're getting closer to the launch of the final major iOS update of the year, with Apple set to release iOS 26.2 in December. We've had three betas so far and are expecting a fourth beta or a release candidate this week, so a launch could follow as soon as next week. Past Launch Dates Apple's past iOS x.2 updates from the last few years have all happened right around the middle of the...
maxresdefault

iPhone Fold: Launch, Pricing, and What to Expect From Apple's Foldable

Monday December 1, 2025 3:00 am PST by
Apple is expected to launch a new foldable iPhone next year, based on multiple rumors and credible sources. The long-awaited device has been rumored for years now, but signs increasingly suggest that 2026 could indeed be the year that Apple releases its first foldable device. Subscribe to the MacRumors YouTube channel for more videos. Below, we've collated an updated set of key details that ...
New Intel Logo

Apple and Intel Rumored to Partner on Mac Chips Again in a New Way

Friday November 28, 2025 7:33 am PST by
While all Macs are now powered by Apple's custom-designed chips, a new rumor claims that Apple may rekindle its partnership with Intel, albeit in a new and limited way. Apple supply chain analyst Ming-Chi Kuo today said Intel is expected to begin shipping Apple's lowest-end M-series chip as early as mid-2027. Kuo said Apple plans to utilize Intel's 18A process, which is the "earliest...
iphone black friday gold

The Best Black Friday iPhone Deals Still Available

Friday November 28, 2025 6:24 am PST by
Cellular carriers have always offered big savings on the newest iPhone models during the holidays, and Black Friday 2025 sales have kicked off at AT&T, Verizon, T-Mobile, and more. Right now we're tracking notable offers on the iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air. For even more savings, keep an eye on older models during the holiday shopping season. Note: MacRumors is...