Infinity Ward has issued a new patch for Call of Duty 4: Modern Warfare, updating to v1.5 this popular first person sequel. This patch some multiplayer bugs (press 'read more' for changelog). A patch for the non-English versions of Mod Tools is also available for download. The PC demo can be found here.
Update: courtesy of icculus.org, an updated Linux server is also available for download.

Call of Duty 4: Modern Warfare v1.5 Patch (10.65MB)

Call of Duty 4: Modern Warfare Mod Tools v1.1 Patch (Non-English) (12.62MB)

Call of Duty 4: Modern Warfare v1.5 Linux Server (52.17MB)