G3M vs Modrix

G3M is a free, open-source desktop manager for GameMaker mods. It can browse supported GameBanana games and install mods from GameBanana, external URLs, local archives, or one-click links. Built-in game entries include DELTARUNE, DELTARUNE Demo, UNDERTALE, UNDERTALE Yellow, Pizza Tower, Sugary Spire, and FRICKBEARS3; users can also add custom games through its Game Manager.

Multiple library profiles can hold separate active mod selections and settings. The Mod Editor combines patches, file replacements, and archive contents, while other tools create and apply patches, merge patch sets, compare files, export diff reports, and convert supported formats. Supported games can launch directly or through Steam where available; Linux users can use PortProton for compatible Windows games. Its Catalog includes themes and plugins, including tools for DELTARUNE saves and custom save folders. Downloads are available for Windows, Linux, and macOS on x86_64 and ARM64 computers. The project states that normal launch mode restores game files after the game closes.

Modrix is a game mod manager with graphical, terminal and command-line frontends built over one shared engine. It is presented as an open-source alternative to Vortex and has built-in support for 86 games, with additional games available through a community plugin registry. A browser extension passes Nexus Mods download links and session cookies to Modrix so it can download and stage files without a Nexus API key. On Linux, the project describes Steam and Proton as first-class options and says Modrix usually detects Steam-installed games for a one-click add-and-switch action. Deployment uses hardlinks where possible, backs up files before overwriting, journals changes for crash recovery and supports reversing deployments. Modrix surfaces conflicts between enabled mods and offers rules and per-file overrides to resolve them. The CLI supports scripting and JSON output, and an MCP server exposes engine functions as tools for agents. The project states that it has zero telemetry and that Lua game plugins are sandboxed. It is GPL-2.0-only and costs nothing.