IW4x is a community-developed multiplayer client for Call of Duty: Modern Warfare 2 (2009), offering players two ways to return to the game’s online experience. The standard IW4x client focuses on community-hosted dedicated servers, where each server may have its own rules and optional modifications. IW4x (mm) instead provides matchmaking, with a friends list and parties available in the client. Players can team up through either version: they can join the same server or host one for friends, or use matchmaking to invite friends directly.

Mods are supported but not required, so players can install either client and play without adding them. The project is open source, with development carried out publicly on GitHub. Visitors can explore the code, browse open issues, consult a contributor guide, or share documentation to help others. The website also provides downloads, technical documentation, system requirements, frequently asked questions, community links, and an archive of earlier client releases. IW4x serves both players seeking community-run servers and those who prefer a more direct matchmaking experience.