UNIX
Unix the OS of internet Gods. Unix has more then one window system with many layouts. It can run all of your basic PC needs only faster. Also it can be run on older computers and speed them up. Unix's net power kills all other OS. To top it all off unix is free.
It has many of the programs that win95 has with a wordprocceser, mail, netscape , etc. It mail program also will let you run your own mail server. It can also be used by more then one user at the same time.
For a 486 or lower unix runs vary well due to the lower resource need to run. It is not to much different then dos just faster. It also will work well with in a LAN. It also will not take much disk space. Also many of the web tools will still run ok on a 486 or lower system.
Unix net power is most note able. With your own web server start your own web site. It is vary power full. When you get on the web you are most likey useing a Unix base system. The really is no other way.
Unix is free and there is more type. You can get on the net with many different types. Some are better then others but mostly the all vary good. Have fun trying them out.