no because garrys mod requires that you have a game that uses the source engine
Yes, you can play online multiplayer.
i want to play garrys mod no downloading and no buying
Buy Garry's mod 10 off of steam.
Yes because you can't play Garry's mod without steam.
Yes. It is a multiplayer game.
Yes, In "Offline Mode".
Not specifically. You need a VALVE game to play Garry's Mod, one of which could be Half-Life 2.
technically yes, there were a few updates it is still called Garrys mod 10 though
Garry's Mod 10
gmod 9, yes gmod 10-no
Garry's Mod has now updated and includes all features of 13 Beta