The fourth instalment in the popular FPS series was released in November 2007. With a marked shift from the series' WWII roots, COD 4 was the first of the series to focus on modern weapons and more intense multiplayer maps.
COD 4 first saw a release in 2007 on PS3, Xbox 360 and Microsoft Windows. An OS X port followed in 2008 while a Wii version came later in 2009. A remastered edition, initially exclusively available with COD: Infinite Warfare, was first available in 2016.
Currently, COD 4 is not part of Xbox One's backward compatibility service. It is also not available on Sony's PS4. The remastered version is playable on either system.
Despite being over a decade old, the COD 4 online mode is still available on most platforms. The Wii version, known as COD 4: Reflex, has had servers issues in the past but appear to be fully functional. As of early 2018, no announcement from Activision has been made on when the servers will close.
Finding an online match is still possible, but there are some problems. The PS3 and Xbox 360 versions are no longer updated, meaning hackers can be fairly common. Long wait times are also common, especially on the Wii version. Currently, the PC version is the most robust.
COD 4 has online death-matches with players connecting via an online connection. No co-op campaign or online death-match option is available, although a local split-screen death-match could be played on the PS3/Xbox 360. The Wii exclusive version had a co-op mode with a second player control a Wii-remote aiming system.
No new retail versions of the game are available for the console, although the PS3/Xbox 360 digital editions can still be bought. The PC and Mac OS editions are also still available in digital-only format. As the Wii's online store has been discontinued, no way of purchasing new copies is available.
COD 4 saw the introduction of a new series of characters who would go on to be series stables. The plot revolves around these British and American special forces agents engaging in military action across the Middle East and Russia with various vehicle and cutscene segments driving the story.
The official updates for COD 4 have ended. Some server maintenance updates occasionally occur.
Players have managed to create private (or "cracked") servers for online matches. These servers are neither endorsed or maintained officially and often require additional workarounds for connection.