It's a game, but still requires a source game to run.
It's pretty much the same deal as "Is RTB v1 a mod or a game".
Nope.He finally gave it its own source engine.
It's a mod you buy, the reason it's a mod is because you have to own another source game to buy it.
or you could ignore the other two people that already said that he gave it support so it DOESN'T need a source game to run
It's a purchaseable mod of the source engine.
here's a better question, how is a mod not a game?
Addon=/=mod. The majority of works called "mods" are generally full games in themselves that only need a base to run off of.