A little over a year ago in TidBITS-407, I wrote about how to run Linux on your Mac. In case you haven't heard of it, Linux is a freely distributable clone of the Unix operating system that's gaining significant momentum, particularly in corporate and Internet arenas - and it's always been popular with programmers and Unix advocates. Although you can't run Macintosh applications under Linux, it does offer fundamental features that aren't available in the Mac OS (like true multitasking and protected memory) and can run an ever-growing set of Linux utilities, servers, and applications, many of which are available for free.
MkLinux DR3 -- My original article covered versions of Linux available for the Macintosh, along with some graphical window managers that put a friendlier face on the command-line world of Unix. Since then, Apple has released a new version of MkLinux, Developer Release 3 (DR3). Prime Time Freeware sells a CD-ROM and a book about DR3, which probably makes MkLinux the most user-accessible Linux for PowerPC-based Macs.
MkLinux DR3 includes a number of important improvements over DR2.1:
DR3 supports a wider range of PowerPC systems, including many NuBus and PCI-based Macs, G3 systems (but not the iMac), some Performas and PowerBooks, plus many clone systems. MkLinux still has problems with some IDE drives and SCSI drives attached via PCI adapters, but these can be worked around by using an external hard disk connected to the built-in SCSI port.
Serial port functions that were problematic with DR2.1 (and critical to printing and PPP, for example) have been fixed and now seem to work smoothly. DR3 also supports audio and multiprocessor operation on some Macintosh models.
DR3 is based on current versions of PC Linux, which means it uses standard Linux file systems and tools, incorporates shared libraries, and uses the popular Red Hat Linux installation procedure.
MkLinux DR3 is available as a free download from Apple; however, the minimal installation is 160 MB, and the full package (including sources) is about 800 MB. Thus, most people will want to spring for the CD-ROM, which is only $20, or the full release plus book, which is $50.
Running DR3 -- I installed and set up DR3 on an external SCSI drive attached to my Performa 6116CD without a hitch by following the lucid instructions that came with (and on) the CD-ROM. Now that DR3 is installed, when my Mac starts up, a splash screen appears that lets me boot into MkLinux instead of the Mac OS.
MkLinux has the normal Linux/Unix command line interface and all the programs that go with a typical Linux distribution, including half a dozen different shells, plus the X Windows GUI and a good selection of window managers that enable extensive customization of the desktop. The MkLinux DR3 CD-ROM also includes independent X Window programs for text editing (nedit), mail (xfmail), telnet (ktelnet), and connecting via PPP (netcfg).
The default window manager is KDE, an elaborate system with its own games, utilities, text editor, and Internet tools (including PPP, mail, news, and an integrated Web browser). KDE runs rather slowly on old machines like mine, so I prefer one of the other managers. By editing the appropriate configuration file, you can choose between Afterstep, FVWM2, FVWM, and TWM. And, of course, you can install others, such Motif, if you want to provide and set up the software. One fascinating aspect of these systems is the capability to select among multiple desktops and command-line terminals within each desktop, all on single screen.
The MkLinux CD-ROM does not include Netscape Navigator or Communicator, but you can download current versions for MkLinux directly from Netscape.
I'm not qualified to comment on using MkLinux for programming, server operation, or other serious work. But for an ordinary Mac owner interested in learning about and playing with a Unix-style multi-user, multi-tasking operating system, I found MkLinux DR3 to be a winner, both easy and fun to use.
More Linux -- MkLinux isn't the only Linux available for Macintosh. LinuxPPC is an independently developed version of Linux for Macs which is also available on CD-ROM; LinuxPPC Release 5 should be available shortly. I have not used LinuxPPC because it doesn't support NuBus machines, but otherwise the two are now considered mutually compatible. LinuxPPC is supposed to outperform microkernel-based Linux implementations like MkLinux, and Release 5 is expected to support iMacs.
If you set Linux up on your Mac and are interested in learning more about it, you might also take a look at the two online courses, Introduction to Unix and Unix System Administration, offered by ZD University: