you can't, its a mod.
infamy mod pack with the tekkit launcher
one with mods in it
He's using a shader mod, not a texture pack.
The Tekkit mod-pack.
well first you need to get hoverboard mod then once you have got that from garry's mod related files you get a skateboard pack and put both of them into addons
Nope.That is if u mean talk in terraria with your voice(using terraria)no.You can use other free programs like skype-you can talk with your mic there and write for free.So just talk in skype and play terraria.
There are a number of addons you can use (These include a SWEP, and a weather pack [weather pack requires wire mod]). Look on garrysmod.org for those addons.You could also be creative and use a Motor and some props plus a smoke mod.
It is probably a mod. If it is superhero mod you must bind a key to +power# Otherwise u must bind something else.
No, you shouldn't need to do that. Whatever Herobrine mod you use, should let him appear naturally, a texture pack won't change that.
Yes you can. You can use it for Single Player AND Multiplayer. It works fine with LAN connections too.
Use da hammma!