The name Apostle originates from the founder of this project, J. Spencer Seidel. Apostle is meant in the sense of bringer of good news. Note that it also contains the magic letters OS.
Look at the install page for details.
There used to be some support, but not any more and there is no intention of supporting any other development platform than Linux and in time Apostle.
For Apostle it doesn't really matter, but on the whole depends on what applications you want to run, you're familiarity with Unix, what knowledge you have of the hardware inside your computer and the money you want to spend. Every now and again several distributions are compared. It's best to look for such a test.
The most popular distributions are (in no particular order):
|The Apostle Project is hosted by|
The Apostle Project website is designed by Guido de Jong.