ATLauncher vs PolyMC

ATLauncher is a Minecraft launcher for browsing, downloading and installing modpacks. Its catalog includes packs from ATLauncher, CurseForge, Modrinth and Technic, and it supports multiple mod loaders and pack imports. Users can maintain separate instances so a new installation does not affect an existing one; the launcher automatically selects the Java version for a pack.

The launcher supports multiple accounts, including Mojang and Microsoft accounts and Xbox Game Pass subscribers. Instance management can install mods, maps and resource packs from CurseForge and Modrinth. It also offers one-click save backups and tools to create and run servers for ATLauncher modpacks. ATLauncher is free and has downloads for Windows, macOS and Linux, as well as a Jar download. Playing modpacks requires a purchased Minecraft account. The site no longer accepts submissions for its own pack platform and recommends Modrinth or CurseForge for sharing packs. For help, users can turn to Discord; contact form requests needing a response are answered within 24 hours.

PolyMC is a free, open-source Minecraft launcher for Linux, macOS, and Windows. It manages multiple accounts, mods, and separate instances, with each instance keeping its own folder for mods, resource packs, settings, and other files. The launcher supports Forge, Fabric, LiteLoader, and Quilt, plus modpack installation from CurseForge, Technic, FTB, FTB Legacy, and Modrinth. Individual mods can be installed from CurseForge and Modrinth for the selected loader and game version. PolyMC also manages worlds, resource packs, shader packs, and Java runtimes, and provides logs plus a way to stop Minecraft after crashes or freezes. Users can customize the instance window and theme. The project says its Qt-based launcher remains light on system resources. PolyMC is licensed under GPL-3, while its logo and related assets use CC BY-SA 4.0. The current macOS build supports Apple Silicon; Intel users need the legacy universal build.