The Left 4 Dead Blog announces beta testing is underway for the Windows and Mac editions of Cold Stream, which will be part of an upcoming DLC release for Left 4 Dead 2. To help with the beta testing, they have enabled in-game bug reporting for the zombie shooter sequel: "We have activated the in-game bug reporter for L4D2. You can currently submit bugs on Valve maps including Cold Stream. This system will eventually be extended to work with community campaigns."