Linux? On the Macintosh? With Mach?

Discover MkLinux—what machines it runs on and what it will do when it gets there.

So, Why Linux?

Need you ask? Linux is the overwhelming favorite among users of free Unix clones. Linux provides Unix features such as true multitasking, virtual memory, shared libraries, demand loading, TCP/IP networking and many other advanced features. Versions of Linux have been ported to a wide variety of platforms, including other PowerPC-based computers, making the Power Macintosh port that much easier.

The Linux community is large, growing, active and involved. This community promotes development and exchange of software and ideas, making it an excellent environment for a new OS product. And, last but not least, Linux is covered by the GNU General Public License, ensuring Apple's contributions will not be used in some other vendor's proprietary product.

Why Power Macintosh?

You may be asking yourself, “Why would I want to run Linux on a Power Macintosh?” After all, the Linux community is overwhelmingly oriented toward Intel hardware. Why change?

For one thing, it's good for Apple and Apple enthusiasts. As noted above, Linux opens the door to a new Macintosh market. Many researchers and scientists who might well find the Macintosh a useful tool, cannot justify the purchase of a second computer system. If their shop runs Unix, a Macintosh just didn't fit in—until now.

University laboratories and dorm rooms are another target. With the availability of MkLinux, users can benefit from the best of both worlds: using Linux for research and batch data processing and MacOS for graphical applications, desktop publishing, and much more. So, Apple may sell the machine, but you get the fun. Think of all those cool MacOS applications just waiting to be explored, not to mention the joy of using the Power Mac's multimedia capabilities under MkLinux.

In keeping with Apple's traditions, the highly integrated Power Macintosh hardware greatly eases Linux system administration. Power Macs are delivered as complete systems. Thus, a Power Macintosh normally can run MkLinux straight “out of the box”, without the addition of cards, chips and other components. Because Power Macs use an intelligent bus such as NuBus or PCI, the OS can deal with hardware configuration concerns such as DMA addressing and interrupt vectors.

In fact, as we tell folks at trade shows: “Once you've installed it, MkLinux is really just Linux. You'll have to give up a few things, of course—DMA vectors, IRQ settings, jumpers, incompatible BIOS code—but basically, it's just Linux...”

Although MkLinux, Apple Computer's Microkernel Linux for the Power Macintosh, has been under development for a few years, it has been available to the general public for only a short while. Apple's first public announcement concerning MkLinux was made at the Free Software Foundation's First Conference on Freely Redistributable Software (February 1996).

Apple announced it was supporting a project with the Open Software Foundation (OSF; now merged with X/Open to form the Open Group) to port Linux to a Mach base and to port Mach to a variety of Power Mac products. The project was initiated, sponsored and funded by Apple Computer.

OSF provided the Mach 3.0 Microkernel (developed by Carnegie Mellon University and the OSF Research Institute) and the engineering team to port the code. (An OSF paper on MkLinux—“Linux on the OSF Mach 3 Micro-kernel”—was presented at the conference.)

Apple's February 1996 announcement predicted the first port of MkLinux would become available in the summer of 1996. Exceeding expectations, the first general release of MkLinux, Developer Release 1 (DR1), became available in May. MkLinux DR1 was followed by DR2, released in September 1996. DR3 is scheduled for release in early spring of 1997.

MkLinux releases tend to incorporate large numbers of changes. Hundreds of megabytes of new or changed material must be acquired, whether by FTP or CD-ROM, typically requiring a complete re-installation. Consequently, full MkLinux releases are made on a relatively infrequent basis (only when warranted by a sufficiently large or fundamental set of changes).

Between releases, Apple issues minor updates via FTP. Some updates provide bug fixes; others introduce new or experimental features. In either case, they are meant to be used with a specific MkLinux release.

What Is MkLinux?

At this point, you may be wondering exactly what MkLinux is. Does it run the MacOS Finder? Does it run X11? Are all the commands I know and love available? For that matter, how is the name itself pronounced?

First things first: MkLinux is officially pronounced “em-kay” Linux, but is often pronounced McLinux. This is in line with Linux tradition, which permits Linux itself to be pronounced in any of several ways. (Li-nucks, Li-nooks, Lie-nooks and even Lee-nooks are quite commonly heard.)

In any event, MkLinux is a complete port of Linux, with a full set of GNU tools and accessories, including X11R6, which runs on top of the Mach micro-kernel. Hence, Mk (Microkernel) Linux. Because MkLinux is really just Linux, it doesn't run the Finder—yet. On the other hand, it does run just about any Linux command you could imagine. (Commands that require Intel-based hardware are, of course, impossible.)