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Apple's first attempt to get an OS running on Mach was, of all things, a Linux port. I don't think the code has been updated since the 2.x kernel series, but if it were to be resurrected, then perhaps there's less of a need to "move on" than the article's author believes.

Apple did study Linux operating system and even made own branch with it, called MkLinux what is still available. Apple's idea was to make Linux a Server-Client architecture operating system instead a Monolithic and get Linux to Macintosh. In MkLinux project they sliced Linux functions to servers and used Mach microkernel with them and so on they got MkLinux. http://www.mklinux.org/

MkLinux were Apple's first Open Source project. Today Apple has dozens of Open Source projects http://opensource.apple.com/release/mac-os-x-1072/

Then Apple went, toke a Mach microkernel, Network protocols, Filesystems and few other OS functions from (monolithic) FreeBSD Operating System to as servers and made nice package with I/O Kit and got a XNU operating system what is a Server-Client operating system by architecture instead Monolithic like the Linux is.

It seems it has nothing to do with the license, as XNU operating system is 100% Open Source and Free Software as OSI and FSF have both accepted the license what Apple used to license that XNU operating system http://www.opensource.apple.com/license/apsl/ http://www.gnu.org/licenses/license-list.html#GPLIncompatibleLicenses Apple just wanted to get Server-Client architecture for their operating system instead monolithic.
Everyone knows the famous debate between Linus and Andrew about how Monolithic architecture is obsolete for operating systems and Server-Client architecture is the future.

Linux is great proof how monolithic architecture for operating system can be very powerful and flexible, when just watching list where Linux really is... Super computers, embedded systems (DVD players, DVB-boxes, Digital TV's), Desktop computers, Laptops, Workstations, Rendering farms, Home/Corporation servers and not to forget... Linux is most used operating system on smartphones... As Apple chose to use Linux as operating system in Android. There are other Linux distributions like Tizen, Harmattan, Bada (using RTOS operating system as well) and many others. Even Nokia bought few weeks ago a Norwegian software company "Smarterphones" what developed Linux distribution "Smarterphones" and Nokia might be planning to replace NOS (Nokia Operating System) and S40 (software platform + GUI) with it and that would mean Linux gets even more support.

In other hands.... while XNU can probably be second popular Open Source and Free Software operating system on markets... GNU projects own HURD operating system what is as well following a Server-Client architecture like XNU, Minix, NT... Has not get stable or ready at all.
FreeBSD is as well monolithic operating system and so is OpenBSD and NetBSD (according wikipedia).

GPL license is great for the community (read it like every human and every country and every government and every corporation) but it is not great for those who are greed, biased and very short sighted people who wants to slave others under their control and control when and what innovation is released and control that with patents and hiding knowledge what other humans has helped them to gain.

Apple's mkLinux (Wikipedia) was based on the Mach 3.0 microkernel. There was a howto to make it work with the standard monolithic kernel. It doesn't really count as "shipping with 2 kernels" but it did run on top of two kernels. It's been pretty much dead since 2002.

OS/2 from IBM also shipped in both monolithic and microkernel flavors. The ill-fated but technically shipped PowerPC version was microkernel-based, but not in the same installable package as a monolithic kernel based OS. This was in about 1996.

I wouldn't be surprised if back in the day, some experimental OSes shipped with both 32-bit and 16-bit kernels.

Yeah the ironic thing was that Apple already had an MKLinux port for their Macintosh systems, and all they really needed to do was integrate the Mac OS GUI with MKLinux...

Right. The company who's business model is paying extra for the same/slightly overaverage hardware would risk GPL lawsuits at a time when the "binary blob" issue was very much unfinished?

Yeah the ironic thing was that Apple already had an MKLinux port for their Macintosh systems, and all they really needed to do was integrate the Mac OS GUI with MKLinux and then just use the OpenStep enhancements because they too are open sourced like MKLinux and could have saved the money they used to buy out Next and bring Steve Jobs back and just do it all better by themselves.

Instead they got Steve Jobs and Next and a much more bigger and bloated operating system than they expected to get.

The other option, besides buying up Be Inc. was to license AROS and then build Carbon and Mac OS systems on top of that as it is already object oriented and based on the AmigaOS that IBM licensed from Commodore to give OS/2 2.0 an object oriented WPS system as Commodore got there already in 1985 before anyone else did, and Apple was basically doing the same thing with OSX that Commodore did with AmigaDOS/Workbench in 1985.

The Amiga was already object oriented even going back to its 1970's roots as the Atari Lorianne project that was basically an Atari 2600 mod to turn the Atari 2600 into an object oriented GUI computer, but the Atari 400/800 projects put Lorianne on the back burner until Commodore bought out the team in the 1980's. The Amiga project predated the Apple Lisa project, and the Lorianne/Amiga team offered Apple to buy them out first, but gave Steve Jobs his idea for the Lisa computer (and later the Macintosh) and he told them no, and visited Xerox's PARC to get some more good ideas.

You seem to be confusing a "distribution" with an "operating system," which is an easy mistake to make (at least for those not entirely in the know).

You obviously don't know who I am if you think I'm not "in the know". *rolls eyes*

Linux is an operating system, whether you like it or not. There's a generally accepted set of core pieces that are shared by pretty much all the usable distros that most people think of as being "Linux". Nobody uses the term "Linux" to refer to the Linux kernel. They call that the Linux kernel. I have never in a single conversation with anyone heard someone use the term "Linux" to refer to the kernel without adding the word "kernel" after it.

From a purely pedantic technological perspective, you are correct. However, language is defined based on how it is used, not based on how an academic says it should be used. As such, Linux is generally used to refer to the Linux kernel plus collectively your choice of Linux distro. See there? I called it a Linux distro. If it were not an operating system, I couldn't call it a LInux distro. I'd have to call it an Open Source OS Distro Based on Linux, or at best, a Linux-based distro. For that matter, you used the term, too.

That said, my primary OS hasn't been Linux-based for a while now, and to be fair, even it has a handful of pieces that my purist approach says should probably be add-on pieces (though it does provide the option to not install them, IIRC). It does not, however, provide a paint program....

Maybe you're thinking of Microkernel Linux (MkLinux) http://www.mklinux.org/ or LinuxPPC/PenguinPPC http://penguinppc.org/?

I guess that what I took for granted as common knowledge is in fact a little-known historical footnote: between Mac OS and OS X, Apple did internal R&D to see if a Linux-based OS could work for them. I can recall at least two such shoot-outs, both falling by the wayside - but gave up googling for them. I can't promise my memory is right, but I think Wilfredo Sanchez was involved in one of these efforts.

The following links are somewhat related to my rant, but doesn't pretend to substantiate them - one is a shameless reminder that OS X lovers would have nothing, my opinion, were it not for Wilfredo's genius:
http://www.mklinux.org/info/aboutfr.html
http://apple.slashdot.org/article.pl?sid=01/02/12/2250215

A microkernel. What, like this? :-)

It could be like MkLinux, basically a modified Linux kernel running atop a proprietary microkernel.

MkLinux was a port of linux to run on top of the OSF MK (Mach) microkernel, which is free as in BSD... hardly proprietary. MkLinux ran on powerpc (PowerMacs), hppa, and x86. The microkernel got reused by Apple as part of (the open-source) Darwin project for MacOS X.

http://www.mklinux.org

It's not had active development for a while now, the active development has been on the conventional Linux, on Darwin and MacOS X!

Has Apple done prepackaged software for GNU/Linux before?

Trying to turn a monolithic kernel into a microkernel has been attempted before. The result was the abomination which is Mach.

http://www.mklinux.org/

Linux can be run on top of a Mach microkernel. Apple supported an effort to do this called mkLinux which ran on both Intel and PowerPC hardware.

One of the advantages/curses of the Mach microkernel that Mac OS X uses is the abstraction between the hardware drivers and the "kernel" that does stuff like manage IPC and disk activity etc., etc. The advantage is the isolation of hardware, the disadvantage is performance. While slower than a monolithic kernel, Mach can be a lot more stable. And with computing power at the level it's at these days I'm not sure how noticeable the difference is for everyday desktop use.

Cringley's idea would make a heck of a lot of sense in this kind of environment, because you'd just instantiate a Windows "kernel" (server in Mach parlance) that provides the runtime profile. This gives you a heck of a robust virtualization implementation, with the Windows and Mac OS X kernels running as peers with equal yet controlled access to the hardware. When us Mac users were running MkLinux it was not unheard of to run a development version of the linux kernel as a Mach server alongside the current linux kernel.

I've always felt Apple's Boot Camp was merely a reason for them to provide the driver glue needed for Windows, and that dual-booting most certainly is not Apple's final goal.

There has been a similar project before. MkLinux for 68K Macs was a port of a Linux to the Mach microkernel (same microkernel used by OSF/1, Nextstep, and OS X).

I dunno dood. It just wreaks of mklinux. I hope you're right though.

Right On! brother.

O.k. Mac OS X is the Mach microkernel with the BSD everything else using Quartz (licensed from SUN) for video.

That sounds like NeXT.
The mach microkernel with BSD everything else. The exception is Quartz as NeXT used X11.

Man, Steve-o must love that mach microkernel. I don't know why I would run Mac OS X as I did truly love my old Mac OS (nods to the boos and hisses, Thank you! Thank you very much!).

You can download something like NeXT for free.

I got turned away at the interface. Way too sugary for me and the price tag. Before OS X new systems were $99. But OS X is $130! And I think but they just recycled half of it!

So, yes. I do not "get" OS X.
And no. You cannot convince me otherwise.

I had been intersted in Linux for a few years and tried out Yellow Dog for about a year before I switched full time.
What can I not do that I did on my old MacOS?
Games. And I prefer those on a console.

http://www.mklinux.org/

Not sure how current it is, and it might be for 68000-based CPUs if I'm not confusing it with another project.

it clearly borrows heavily from some well known BSD licensed unixlike codebase (almost certainly Darwin, given their claims of Mach kernel services).

There was something called XMach at one point that's virtually disappeared, this too was a BSD kernel for Mach.

It's worth noting that Mach based Linux also exists, in the form of MkLinux.

http://www.mklinux.org/

Cough bloody cough. What's your point? Linux exists on the Mac.

Hell: Linux.org is where you want to go if you're going to be pedantic.

1: I wouldn't have a real good grip on how much Solaris had to do with it, except that Solaris hasn't been targeted at bottom shelf PC hardware and challenging the Windows desktop, until very recently. I didn't start messing with Solaris on a P200 2 years ago, I started messing with Mandrake. I haven't purchased Solaris licenses for the 4 or 5 machines that would otherwise be running Linux. Solaris probably wouldn't run with full hardware support on my laptop and I'm not interested in bugging Sun to see if maybe they'll add that to the next version. It may be some kind of deity wherever you work or go to school, but the rest of us don't pay for what we don't need, regardless of whatever spiffy features it has that make it *oh so much* better than Linux.

2: I believe another reply has addressed this, but since you are not aware, Apple partially sponsored a Linux kernel/Mach kernel system called MkLinux that still runs on old Mac hardware. This sounds very much like an "option or influence" related to Apple's adoption of a hybrid BSD/Mach microkernel for their new OS. (MkLinux)

3: I didn't say Linux was/is better, I just said it forced everyone else to improve. By analogy, to help you grasp what I'm saying: If someone was giving away brand new Chevy Cavaliers to anyone who asked, how many people would run out and buy a luxury car instead? Only those who really, really, really want or need them.

4: I'd be more likely to toss them at anyone who modded up an anonymous coward.

Not trying to be negative, but is the base system & kernel open sourced from Apple or didn't Apple take somebody else's work and lock it down? In other words I have the understanding that Apple took FreeBSD which is somebodyelses hard work and added their own stuff on top without releasing the stuff on top or how it interacts with the stuff provided by FreeBSD, or any changes they might have made to FreeBSD to make it better.

Apple bought a company called NeXT that had a proprietary BSD386 based OS running on the Mach Micro-Kernal. In the company was an employee who had done a large amount of the original work creating the Mach Micro-kernal. Apple took the NeXTStep / OpenStep operating system as the basis for its Mac OS X operating system. Apple ported it to the PowerPC Chip sets, fused it with knowledge gained from Apple's earlier Unix OSes A/UX and MkLinux and then re-synced the userland with FreeBSD 4.x (now they sync the userland to FreeBSD 5.x).

This might need more explaining. Unlike Linux where all each distribution has the same Linix kernal (sometimes compiled in different ways, but still the same kernal code), BSD branches do NOT have the same kernal. NetBSD, FreeBSD, OpenBSD, DragonflyBSD and Darwin(Mac OS X) are each different kernal code bases. Sometimes they share components / code, but mostly they do not. The different branches are designed to provide the same working userland to users and applications. By "re-synced the userland to FreeBSD" Apple did little more then confirm their OS is compatible with FreeBSD and either updated their own /bin and/usr/bin applications to feature / function compatibility with FreeBSD or ported the FreeBSD apps over, whichever made the most sense. Again all work was done by Apple Engineers.

So what Apple did was not "take somebody else's work and lock it down" but rather take the work Apple Engineers and the Engineers of a second company Apple bought (and retained the employees of) and release the code for no cost onto the internet.

OpenDarwin.org

While this is certainly valid given the license of FreeBSD, strictly speaking that's just being a thief as far as I'm concerned.(Yes I know MS has done this too with it's Unix Services layer).

If someone gives something to you for free, it is not stealing. The only people who are allowed a moral objection to how you use the freely given object are the ones who gave it to you. Far from being upset at it, BSD users "shouted for joy" that Apple choose to base their new OS on BSD. Daemon News: Apple -- What's in it for BSD?

I also understand however, that Apple has given some changes back to the KDE community for the web browser, locking up other changes however behind a proprietary license. In other words it looks to me like Apple is trying to garner some favor while stealing the "open source" community blind.

Every single piece of OpenSource software Apple has used (irrespective of the license it was released under and the requirement, or NOT, to release the code) they have release the code to. The code is available either through the Darwin OS , one of the other Apple Open Source Projects, or by giving the code back to the original developers. In addition to that Apple has also released code that was never before opensource, with projects such as OpenPlay , Darwin Streaming Server and

I think it only runs on Power Macintosh, and it's the only flavor of Linux that will work on NuBus (first generation) Power Macs.

Unlike some folks, I've been tracking the relationship between Apple and the Linux world for a while now. In fact, my original impetus for becoming a switcher (in 1997 or 1998, no less) was the introduction of MkLinux. That's what convinced me to get rid of my PC and buy a PowerMac 7300.

MkLinux was a project within Apple to port the Linux kernel, along with the necessary GNU tools to make a complete OS, to the PowerMac architecture; this was accomplished by running the Linux kernel as a personality on top of the Mach microkernel, which was ported to the PowerPC PREP/CHRP architecture.

With the advent of other Linux ports to PowerPC, most of which involved running the Linux kernel monolithically rather than hosting it on top of Mach, MkLinux was mothballed and quietly discontinued. However, the engineers at Apple learned a lot from the process, and this set the stage for the eventual merger with NeXT and the Rhapsody project, which evolved into Darwin and OS X. Specifically, lessons learned from porting Mach to PowerPC and hosting various OS personalities on top of it proved invaluable.

It's fair to say that Apple contributes a lot to the Open Source world, and therefore the Linux world by extension. (KHTML has been improved a fair bit by Apple engineers since they picked it as the rendering engine for Safari.) Of course, Apple's contributed more heavily to the *BSD communities.

Suffice it to say that I don't think Apple is worried about Linux, at least not in the way that Microsoft is. I certainly don't see any enmity between Apple and the Linux communities that you seem to be implying.

What software does Apple make available to the Linux world? Well, besides their contributions to KHTML, they have Quicktime Streaming Server (or whatever they're calling it today) and various other Open Source projects that are free for the Linux community to use. Apple's Rendezvous code is open, for instance, and it's a pretty good implementation of ZeroConf as I understand it.

Of course, when push comes to shove, Apple will try to promote their own products over other products. What else would you expect of them? But failure to endorse Linux doesn't mean Apple and Linux are "enemies." Apple's big selling point is ease of use and ease of administration. So far, the Linux world doesn't have this across the board. Since Apple tightly controls the look and feel of everything Macintosh, as well as other aspects that make up the user experience, I don't think Linux will ever quite catch up in this arena. Some things can't be commoditized, and Open Source (for all its benefits) doesn't lend itself to the development of seamlessly integrated software suites with consistent user interfaces. Should that ever happen in a big way, then maybe Apple might re-think its relationship with the Linux world, because then Linux will be competing on Apple's turf; right now, though, there's not much competition.

Check out MkLinux. It is a Linux distribution that runs Linux as a layer on top of a Mach microkernel. Prett cool to do a 'top' and see linux as one of the running processes...

I did that on my mac in 98 with MkLinux.

Hint: don't mount the same partition as / with read-write under both running kernels.

c) Apple did not move BACK to UNIX, because Apple never used UNIX before.

Apple is afraid of Linux and they in No way want to give creedence to it being an acceptable platform for desktop use.

Yeah, right. That's why they officially allow Terra Soft to sell their hardware with Linux preinstalled. Apple is a hardware vendor. As long as they can charge you $2999 or more for a computer, they don't really care about which OS you choose to run on it. Apple always supported the PPC Linux efforts - first with MKLinux (mind you, an Apple-branded Linux distro!), now with their blessing for Terra Soft.

OS X is based on the Mach kernel with a BSD userland.

PPC did not exist until Apple, IBM, and MOT got together to design it. On the other hand Power (or RS6000) did exist and is what PPC is based on which was running AIX. Linux on PPC did not exist until Apple added support for it that is what I was trying to say; IBM was not the one who first added support for it, Apple was and that was back in Summer of 1998 see www.mklinux.org.

MkLinux

Here's what you're looking for...microkernel Linux. Sorry, I couldn't fine any screenshots.

QNX has been the only company so far to commercialize a microkernel OS.

I love QNX, but they definitely aren't the only company to commercialize a microkernel OS. Apple, while late in the game, are shipping some big numbers. Of course, don't forget NeXT before them, or for you penguin-heads, MkLinux.

I guess I should have included links in my earlier posts. ;) If you want to look for a user group or find information about them, look here. For the stores, look here. There is lots of great info on the apple site. It is not all marketing. You can download all the old versions of the apple OSs (or used to be able to) and there is information about hardware, software, consultants, and training. Apple is well aware they have to work a bit harder to advocate their platform. This is why I think we in the Linux community can learn from their examples.

By the way you can also check out their Open Source Offerings and there is a Darwin for x86. It does not give you aqua, it is essentially a BSD, but you could get an idea of the underlying structure. I have never installed it, so YMMV. You can also still check out the linux they left behind.

Apple indeed quit working on Linux, but it did at one time distribute a linux system called mklinux. It was based on RedHat and had a mach kernel rather than the normal Linux kernel. Whether that makes it not Linux anymore is certainly an interesting academic question. Of course, Darwin ended up taking away a lot of the development that used to happen on mkLinux. Apparently work has gone slowly, as in the 5 years or more I have been looking at this project off and on there still has not been a "release" though it appears the site is being updated and release candidates being released.

Except they did do, it's called Darwin. In a similar way, MKLinux isn't running a stock Linux kernel on top of Mach, it was a modified version.

AFAIK, development is hardly progressing at lightning speed, but don't take my word for it - look here

mac os is much more than bsd-like. and there are other mach based distros of linux and bsd; mklinux comes to mind. yes that's right, mach kernel linux. i've used it, it ain't all that, but it is out there.

and yes, most of em wouldn't care to know the difference between unix and tunics, but those of us that know, appreciate Why the mac is special

Try:

MkLinux and
Mac OS X

Of course, both are somewhat more successful than the HURD...

Just a note on putting linux on a 6100: You do know it is only supported by MkLinux, right? (It is a first generation NuBus Mac.) Might save you some hassle. (Not that it is easy to install...)

Well, it's certainly not the microkernel that's holding things back. BeOS and Mac OS X both use microkernels. There were UNIX emulators for Mac OS Classic running on Mach, and MkLinux had a Linux kernel running in user-mode on Mach on both x86 and ppc platforms before any of this User Mode Linux business.

hey both live in kernel space. So why are they using Mach? I dunno.

Also Mach offers functionalities that the BSD layer does not. Some parts of Mac OS X rely directly on Mach facilities - for instance for distributed objects. Posix threads are directly mapped to Mach threads.

Mklinux is a joint project between OSF and Apple. It is an implementation of Linux on top of Mach 2.5 (Darwin is based on Mach 3). It mostly ran on early PPC machines (x100 models, the so called Nubus Powermacs) Althought MkLinux was discontinued it served as a proof of concept that you could run a microkernel architecture on a Mac. Contrary to Darwin, MkLinux has the linux layer and the Mach layer in different address spaces.

I think xtunes is really too similar to iTunes. The deveopers should change the name to somethin else before Apple lawers get after them ...
Does the beast runs on linux PPC ?
This is one thing that bugs me in the inux world , the lack of support for non IA-32 architectures.
Apple used to be more linux friendly (but that was way before they purchased NeXT and got a "modern" unix, do not read A/UX here ...).
On the same scale of things is there any effort to bring a quiktime player for linux ? would people use such software ?

Apple hosts a mailing list for MkLinux. This will be your most useful source of information if you pursue the MkLinux route, as much of the information on the MkLinux website is out of date. The people on the list are very friendly and helpful with even the most absolute-newbie questions (and if your Linux experience is limited to the PC realm, you will have some newbie questions relating to Linux on Macs). There are searchable archives of the list as well. Good luck with your quest.

mklinux will work on almost all nubus macs.

• Yellow Dog
• Linux PPC
• Mac On Linux
• 68k Linux
• MkLinux -the original Mac distro

I want one, just to have a home server that is not x86, is this board really for real???

Depending on what type of server and how heavy of use it's going to be getting, then why bother with a $600 motherboard that you just have to buy more parts for anyways? If you're willing to do a little messing around, just get an old PowerMac for cheap (make sure it's at least a 2nd generation PowerMac as anything before doesn't have PCI, and try to avoid those with the 601 processor, especially the 7200.)

Although it's not quite the same thing that you want to use it for, my router is a PowerMac 7600/132 (604 processor at 132MHz, 92MB of RAM) which was purchased for ~30 USD (+ shipping). As of this post it's been running for 32 days, 7 hours and 24 minutes without any sort of problems.

Only possible problems are the hardware quirks, but NetBSD has a good model support page detailing most of them for anyone who wishes to run any *nix, and the fact that if there isn't enough storage space then you may have to pay a bit for it depending on whether or not the drives are SCSI or IDE. But, with PPC you tend to pay a bit more for the hardware anyways...

Either way, PenguinPPC is a good place to check out info on Linux on the PPC architecture. (And for old Mac owners, MkLinux is a good place to check for solutions to problems that may be missing from the documentation of your chosen distro (*cough*Debian*cough*) )

Is Mac OS X a Threat to Linux?

In short, yes! On March 24, Apple Computer, Inc. released its next-generation operating system, Mac OS X (the "X" is pronounced as "ten," for the version number of the operating system) to Macintosh addicts around the world. While this isn't such a big deal to some, others view it as a new beginning that could squash all thoughts of a desktop Linux for the general public.

What's this, "Apple out-maneuvering Linux?" you say? Well, maybe not as a server platform for the immediate future, but just think about this for a second: Would it be possible for Apple to deflate the hopes and dreams of developers worldwide of bringing Linux to the desktop? The short answer to this is yes, but it's more complicated than that.

Aside from the fact that an apple is a fruit and a penguin is a flightless waterfowl, there used to be a big difference between the Apple Macintosh operating system and Linux. Apple had a nice GUI; Linux did not. Linux had a command line; Mac OS did not. Linux is a multitasking OS that supports multiple processors; Mac OS is not. Linux runs on just about anything these days; the Mac OS runs on, well, Apple equipment. Linux is free (well, sort of, depending on your method of install); Mac OS X will set you back $129.

So, the lines were pretty clear about the differences between Linux and Mac OS. But lately, that clarity has been blurred as Apple rolls out Mac OS X to the public. The new Mac OS now has preemptive multitasking and support for up to two processors, which is still a far cry from Linux's support for up to 16 processors, but it's a move in the right direction.

Traditionally, the only control Apple users had over their system was via the Control Panels and scripting system functions with AppleScript, MacPerl, or ResEdit. However, with Mac OS X's BSD base, Apple users were given something they've always wanted: a latch to take a peek into Apple's core.

At the core of Mac OS X is a kernel built on the Mach 3.0 kernel, BSD 4.4, and Darwin (Apple's open source kernel project), giving network and system administrators the ability to use Unix programs and add them to their Macintoshes. When combined, these components offer a rock-solid operating system that's hard to beat. (OK, I know that Mac OS X has its fair share of bugs, so no flames, please.)

One of the advantages of Mac OS X is that it now offers Macintosh users with a command line on top of a slick, stable GUI, known as Aqua. With OS X's BSD core, Macintosh users will now be able to use GNU software. This means they will be able to run tools like Emacs, vi, Apache, and even XFree86 and the GIMP (something that Adobe Systems should fear). If you're looking for a place to download ports of GNU tools that run under Mac OS X, you should visit the GNU-Darwin Project on SourceForge.

One of the downsides of OS X is that it requires you to have a native G3 or G4 processor. This means you have to be running a G3 Mac, an iMac or iBook, a PowerBook G3 or better, or any of the G4 models and above. So, if you have an older 604 PowerPC-based Mac, you can't run OS X (that is, unless upgrade manufacturers, such as Sonnet Technologies release updates to their processor software). For now, though, if you want to run OS X your best bet is to run it on native hardware.

One group that stands to lose a chunk of the market is the Mac-based Linux distributions, such as MkLinux, LinuxPPC, or Yellow Dog Linux (YDL) from Terra Soft Solutions. Up to now, these were your best options for running Linux on the Mac, with LinuxPPC and YDL leading the pack. But OS X changes this landscape significantly. The downside to running Linux on your Mac in a dual-boot configuration (as with Windows) is that if you want to access any of your Mac apps, you had to either reboot, or install and run Mac-On-Linux. Neither option is ideal, but now OS X allows you to work in the command line, and run your Mac apps right along with them--no rebooting required.