An update has been released for Left 4 Dead 2.

- Fixed a new bug causing some items to not transition between levels.
- Added missing model precaches to Left 4 Dead 1 Mutation mode.

An update has been released for Left 4 Dead 2.

- Fixed a new bug causing some items to not transition between levels.
- Added missing model precaches to Left 4 Dead 1 Mutation mode.

An update has been released for Left 4 Dead 2.

- Prevent a crash if a material overflows the index buffer.
- Zombie population fixes for Left 4 Dead 1 Mutation modes.
- Fixed some material properties on Left 4 Dead 1 common infected models.

An update has been released for Left 4 Dead 2.

- Fixed a crash after failing to load a map.
- Fixed a crash caused by missing materials.

An update has been released for Left 4 Dead 2.

- Fixed a crash in particle systems loaded from Add-ons.

An update has been released for Left 4 Dead 2.

- Fixed security issues reported by Justin Taft from One Up Security, LLC.

An update has been released for Left 4 Dead 2.

- Fixed a potential remote code execution exploit.

An update has been released for Left 4 Dead.

- Fixed a potential remote code execution exploit.

An update has been released for Left 4 Dead 2.

- Fixed a server lagging exploit.
- Fixed some reported security exploits.
- Fixed key bindings not displaying correctly when using the Xbox 360 controller.

New EMS scripting features:
- Added a new interface for reading/writing entity network and data table fields from script. Use "script_help NetProp" for interface details.
- New script function "TakeDamage( amount, type, attacker )".
- New script function "GetNetworkIDString()".
- Added "timeofday" keyfield to the world entity.
- Support auto_spawn of witch bride.

An update has been released for Left 4 Dead 2.

- Fixed an issue on some MacBook Pro models that prevented the game from rendering correctly, resulting in a blank or white screen with game running in the background. This fix required a change to the minimum spec from MacOS 10.6.4 to MacOS 10.7 (Lion) or higher, which matches Steam's minimum spec.