It's for people working or residing in Ile de France, not for visitors, though I suppose if a visitor wanted to fill out the form with a Paris address and phone number, they would probably be able to get one.

The Carte Orange is also intended for people working or residing in Ile de France (because it's subsidized by the government), though they usually will sell it to anyone who requests it.

It's probably easiest for most people to stick with the Carte Orange, which won't be disappearing anytime soon.