I'd like to gain some info on the main OSs I've heard about: Linux, BSD, and BeOS.

Mainly, I would like to know:

1. Main type of user/use

2. Advantages/Disadvantages

3. Any more useful info (or not particularly useful, either one)

Info on other OSs also appreciated, and please, no flaming on any OS, present arguments thoughtfully.

Thanks for all input.