Exodium is a free, open-source application that allows users to run classic computer games from the eXo collections on modern operating systems like Mac Apple Silicon, Linux, and Windows. These collections include thousands of games originally designed for DOS, Windows 3.x, Windows 95/98, and ScummVM, all of which are pre-configured to run with minimal setup. Exodium acts as an alternative to the official Windows-based launcher, LaunchBox, and lets users browse the game catalog without downloading anything upfront. When a game is selected, it is downloaded via BitTorrent and runs in the appropriate emulator, making it easier for users to access retro games without needing to install each one separately. The eXo collections are vast, containing games from multiple eras of computing. While the original eXo interface is not officially supported on Mac due to a lack of volunteers to adapt it, Exodium provides a workaround for Apple Silicon users. The launcher also supports multiple language packs, including German, Spanish, and Polish, and is compatible with different eXo modules like eXoWin3x and eXoScummVM. For eXoWin9x, which emulates real versions of Windows 95/98, Exodium boots the system under DOSBox-X or 86Box, downloading about 2.5 GB of system images and data in the process. Exodium includes several features to enhance the retro gaming experience, such as support for MT-32 and General MIDI music, with sound banks and ROMs retrieved directly from the collection. It also provides access to game manuals, box scans, magazine ads, and preview videos. Users can apply CRT shaders to simulate the look of old CRT monitors, adjust CPU cycles for performance, or manually edit the DOSBox configuration for more control. However, on non-Windows platforms, some games that were originally configured for DOSBox ECE may run under DOSBox Staging with automatically translated settings, which can lead to a less consistent experience due to differences in emulator features. As a BitTorrent client, Exodium connects to the eXoDOS network and shares data with other users by default. Users can disable sharing during installation or later in the network settings, which will reduce their upload speed significantly but not stop it entirely. If the eXoDOS collection is already stored on a local disk, the torrent client does not need to be active for the games to run. On macOS, the application is not signed with an Apple Developer ID, which might trigger security restrictions. Users can bypass this by manually moving the app to the Applications folder and using terminal commands or a tool called Sentinel for a simpler solution. On Linux, Exodium is not strictly necessary since official patches already support eXoDOS, but it remains useful for other eXo modules not covered by those patches. For Mac users, an unofficial patch is available but requires additional setup.