An update has been released for Left 4 Dead.

- Fixed exploits used to crash remote servers.

An update has been released for Left 4 Dead.

- Fixed some exploits used to crash remote servers.

An update has been released for Left 4 Dead.

- Fixed several crash and remote code execution exploits.

An update has been released for Left 4 Dead game and authoring tools:

- Fixes for several crash and remote code execution exploits.

An update has been released for Left 4 Dead:

- Fixed an exploit that could force votes to pass without notifying other players.
- Added protections against malicious network packets.
- Integrated several exploit fixes from Left 4 Dead 2.

An update has been released for Left 4 Dead:

- Fixed several vulnerabilities and exploits, reported via HackerOne.
- Localization fixes, added Latin American Spanish.

An update has been released for Left 4 Dead.

- Fixed a potential remote code execution exploit through malformed file uploads. Reported via HackerOne.

An update has been released for Left 4 Dead

- Fixed Authoring Tools failing to write to disk

An update has been released for Left 4 Dead

- Fixed several potential RCE exploits.

While cleaning/moving our offices around (all our desks at Valve are on wheels so we can have desk races), we discovered this old, long ago used Zombie decision making tree. It was created before our session with Mike Patton to record the common zombie sounds. While it is near indecipherable gibberish thanks to bad penmanship, it shows not at an AI level how a zombie behaves but all the speech opportunities and transitions.

Our favorite is the top. Lay Down? Nope. Want to vomit? Sure.

<img src="http://media.steampowered.com/apps/l4d/images/chart_thumb1.jpg">