But the source code remains open to everybody, so everybody can tinker with it and add to it. This is in big contrast to both Microsoft and Apple, who do not share the source code of their operating systems. By 1997, an estimated 3,000,000 people were using it. Anybody in a computer career familiar with UNIX should be able to operate it without much problem. The rest of us probably would have had more problems until the recent commercial forms came out.
Users tend to be fanatic zealots who advocate that it attain world domination.
It is much more reliable. Those of us used to rebooting Windows at least once a night understand the appeal of that. It is also good for network systems. Networks are becoming increasingly important and common in businesses and now even in homes. It can cut the cost of networking a lot.