Zombie Panic: Source v1.3
The Zombie Panic team are excited to announce that Zombie Panic: Source v1.3 is now available for all of you who own a source game through Steam. To install ZP:S v1.3 click the [+] Next to "Not Installed" in your Steam My Games list and double click on Zombie Panic! Source.
You will now receive automatic updates through Steam when you log in or run the mod through steam.