How it works
- Finds the runtimes already installed and identifies the version and architecture of each.
- Downloads what is missing from Mojang, hash verified.
- Older game versions get the Java they actually accept.
- The option offered is always a version that exists to download.
Live catalog
- Minecraft versions come from the official Mojang manifest; no fixed list that goes stale.
- Client jar, libraries and assets, all hash verified.
- What has not changed since last time is not downloaded again.
Memory
- The default limit of a new instance is computed from the machine RAM.
- Any value can be set, and the launcher warns when it does not fit.
- The instance JVM arguments reach the game.