Mike, let me take a stab. Linux is "freeware" version of UNIX for x86 PCs. Its free in the sense that anyone is free to download and use it. It is a "cooperative" effort in the sense that developers from around the globe add features/drivers/utilities to the base kernel and hence and operating system is born. A number of companies, Red Hat being the most prominent take the free version and many of the well tested features, and "sell" it very cheaply. Basically, their value add is the support.
It has a following among techie backroom types for a number of good reasons, price being near the top of the list. It "competes" (so to speak) with Windows NT server. We all know how much MSFT sells that POS for (just kidding, I'm long MSFT for 3 years now, and proud of it). Linux is supposedly more stable, more scalable, and more lean than the bloated pig NT.
An interesting point is that the Apache Web Server software (another freeware app), running on Linux, is by far the most used web server combo on the planet, far "outselling" NT IIS, and Sun, and everyone else.
The big box guys, like Dell, CPQ, and IBM have all recently announced that they will preload Apache and Linux for those corps that request. They hate MSFT as much as you guys here do <g>.
Hope this helps.
Gary |