This is the fully updated (1.0.0.9) release of The Psy Family's Left 4 Dead.

This is playable online, to an extent. You can directly connect to servers and do LAN using Hamachi. See the tutorial here. 
http://www.thepsyfamily.net/forum/index.php?topic=4998.0

The only configuration needed is to enter a name at the end of rev.ini in the root folder, then start left4dead.exe

This is the FULL release by Psy, just extracted and updated then recompressed. Only things removed are the intro videos for the sake of saving some space, and because it saves a couple clicks as the game goes right to the menu on startup.