An open-source fork focused on user freedom and redistributability.
Offered a simple interface to select and download various Minecraft versions, including early releases and snapshots.
A for a legitimate paper on "Version Management in Game Launchers: A Case Study of Semantic Versioning" — including sections on:
Ensure you have the latest version of Java installed. While the newer Minecraft versions use bundled Java, the launcher itself sometimes relies on system Java installations.