IrfanView

IrfanView at a glance

IrfanView is a long-standing, popular free (for personal use) Windows image viewer and lightweight editor, valued for speed and broad format support. IrfanView ships regular releases; it's a user-space application.

For admins IrfanView parses a very wide range of image and media formats, some via plugins — and parsing untrusted files is exactly where image-viewer vulnerabilities live, so keeping it current closes those fixes. Source it from the official site (avoid bundled-installer mirrors that add unwanted software), and mind the licensing (free for personal use, paid for commercial). The plugin pack extends format support and carries its own updates. New versions bring format support and fixes. In managed environments, keep it in the software inventory and patch cycle. Opening images from unknown sources is the risk to keep in mind; a current IrfanView closes known parser flaws. Patchletter surfaces new IrfanView releases.