If you look at the history of Unix, you will find that it is strewn with different flavors of Unices, each doing a particular task in its own way, there being no synergy between them. Inspite of all this, some of the Unix flavors have succeeded in surviving the Linux onslaught.
As a Linux user, have you ever wondered what differences each Unix flavour have from each other ? Yes? Then look no further. Bhami.com has compiled an extensive table detailing the differences in commands used for executing a task in various flavors of Unices and Linux which I found really interesting. It is a real eye opener for anyone interested in computing on the Posix platform.