You can get them form Garrysmod.org. http://www.garrysmod.org/downloads/?a=view&id=56957
Or if you own the actual game or demo (You can't get the demo any more), you can use CGFScape (http://nemesis.thewavelength.net/index.php?p=26) to extract the models materials and particle folders in the pak01_dir.vpk in the \Steam\steamapps\common\left 4 dead\left4dead folder to the Garrysmod/addons folder and add an info.txt with the folowing information:
"AddonInfo"
{
"name" "L4D Content"
"version" "1 *****"
"up_date" "July 25 2009"
"author_name"YourName "*****"
"author_url" "http://www.valve.com"
"author_email" "you@email.com"
"info" "The Content From Left 4 Dead"
"GCFRequires"
{
//"0" "220"
}
}
Consult this thread for further help and/or instructions....
http://www.facepunch.com/showthread.php?t=642683
Buy Garry's mod 10 off of steam.
technically yes, there were a few updates it is still called Garrys mod 10 though
Garry's Mod 10
no because garrys mod requires that you have a game that uses the source engine
Garry's Mod has now updated and includes all features of 13 Beta
Garry's mod tornado
Steam is the company that has created Counter strike, half life left 4 dead and many other great games like garrys mod ect.
Steam
yes
You Do Not Get Garrys Mod Serials, You Buy it Off Of Steam Which can be found at steampowered.com its usually about 21 United States Dollars
E
There is, 10$ Steam