Linux for Die-hard Mac Users
This article represents an attempt to briefly introduce Linux to Mac users. Linux cannot be ignored these days - its installed base is about the same as MacOS and growing very rapidly, smashing mostly Windows NT, Novell, and sometimes, even MacOS X Server. Unfortunately, Linux and Mac users often have completely different mentality. Linux fans sometimes qualify Mac as closed, vanishing, and soon to be obsolete platform, while die-hard Mac users call Linux awkward and clumsy UNIX clone. Neither is true, none of the platforms is universal and for everyone, both Mac and Linux can coexist in either office either production environments, utilizing advantages of both.
There are no questions if Linux popularity will grow, it certainly will, and not only among personal computer, workstation and workgroup server users. Recently released Linux 2.4 kernel allows effectively deploy Linux on almost anything from embedded microprocessors (which accounted 90% of all microprocessors sold), used in handheld computers and electronic devices; to SMP (symmetric multiprocessing) enterprise server platforms (with up to 16 CPUs and as much as 64 GB of memory) and even clusters with 100+ CPUs.
Open Source Tidal Wave
Linux cannot be understood without a clue of open source software, because Linux is an open source OS.
The idea of open source, or GNU General Public License (GPL) is to give everyone access to source code and freedom to modify and distribute them, either for gratis either for money, at no extra charge or licensing fees. However, all modification have to be made available at the same open source licensing terms.
Commercial developers in most cases do not use open source libraries because they do not make their sources available to the public. It does not mean that commercial software can not exist on Linux. If one is going to distribute modified version of Linux, he must do it under GPL license, which allows everyone else (agreed with GPL, of course) to use his sources, however, if the same person or company has a software which just runs on the Linux and do not explicitly include portions from GPL libraries, there is no obligation to publish source codes. In other words, GPL license acts like a virus. Misunderstanding of GPL license sometimes scare commercial developers. Anyway, both open source and commercial software do coexist on Linux!
Another question is usually how people are going to make a money writing software if anyone else can use, modify, and sell it. Many Linux people do not sell software, they sell professional services and solutions. In reality, if some basic software is free, it does not mean it can be used by the end user as is. Probably no one would be happy to have a heap of bricks and stones instead of house.
Thus, the Linux industry is about to sell customized turnkey solutions without extra fees for closed and proprietary technologies, which have certain chances to become orphaned when manufacturer faces financial problems or falls under acquirement and/or restructuring.
Again, traditional software business (fee per each user license) exists on Linux, too. Nobody said you are obliged to give away sources of your product just because it runs on the Linux!
Many people are confused with large number of Linux distributions available on the market. First of all, all Linux distributions, except few very specialized, are based on the same code base. There are two major branches, first one is Debian, maintained by the group of 500 volunteers; and second is the Red Hat distribution, from the Red Hat Inc.
Debian/GNU Linux is a kernel independent, huge, and pretty conservative distribution which includes only software covered by one of Open Source Licensees (GPL, BSD, Artistic, etc.). Thus, even KDE desktop have been excluded (but can be downloaded separately). Debian is available for Intel x86 and compatible, PowerPC, Motorola 68k, Alpha, and SUN SPARC (work for MIPS and ARM CPUs is in progress). Debian installer is ancient looking but very functional and feature rich, making installation of over 3950 (!) software packages much easier by means of using profiles (e.g. C++ Development, WEB server, etc.), which allow to automatically select necessary components for particular needs. Debian received investments from VA Linux and SGI. Corel Linux, Progeny Linux and Storm Linux distributions are all derived from Debian. Debian group currently working on the new Linux kernel called "The Hurd". Its goal is to replace monolithic Linux kernel with object-oriented microkernel. Another group currently adapting Debian to BSD kernel.
(Red Hat Package Manager) based distributions are the most popular.
I will not list all of them, but rather those available on the Mac:
Linux and Yellow Dog Linux
(its very possible that Mandrake
Linux will enter PowerPC market, too.). Some like LinuxPPC and
Yellow Dog Linux are a PowerPC recompilation of Red Hat Linux with
some platform-specific additions (e.g. bootloader, installer, partitioning
utility), while other, like SuSE Linux, is a branch of its own.
Linux is not a derivative of Red Hat Linux. In fact, SuSE appeared
in 1992, and Red Hat in 1993. First versions of SuSE Linux were based
on SLS Linux and Jurix Linux (the last, in turn, has its roots in
Slackware). Later SuSE Linux acquired Red Hat Package Manager.
Mac Linux called MkLinux based
on the Mach microkernel, not on the monolithic Linux kernel, and looks
like being almost abandoned. MkLinux is the only Linux which can be
installed on NuBus based Power Macs.
Linux is a mini-distribution (roughly 200 packages), developed
for experienced users who would like to compile and optimize Linux
during installation themselves. So far (January 2001) Rock Linux tested
on the iMac only.
Linux from Scratch (or
LFS) is for the people who are not satisfied with any distribution
available today. Linux from Scratch, as name suggests, is a build-yourself
Linux software usually comes in RPM (Red Hat Package Manager) format. Debian uses its own deb format, but special tool called alien can convert and install RPMs. Software which is still at development stage often distributed as compressed archive of object, script and configuration files (tar.gz or tgz). Almost all Linux software available in source code format, what means that you can compile it yourself using make utility and GNU development tools, which are included with every Linux distribution.
So, after all, what is the difference between distributions?
How large is Mac Linux installed base? LinuxPPC Inc. president estimates around 250,000 - 500,000 (by January 2001). Based on the information from mailing lists I can judge that majority of Mac Linux run on the PowerPC 604 PCI based machines (7300, 7500, etc.) and Beige G3, usually as WEB and mail servers. Its a fixed fact that Linux allows to recycle many old Macs, which are not suitable for daily work anymore.