Prism Launcher Technical Glossary

Clear definitions of Minecraft modding and launcher terms: `.mrpack`, Fabric vs NeoForge, JVM heap flags, G1GC/ZGC, and Exit Code 1.

Section

Glossary

Platform

Windows 10 & Windows 11 (x64 / ARM64)

Mod Platforms

Modrinth, CurseForge, FTB, Technic, ATLauncher

Installer

Available at /download

How Prism Launcher Technical Glossary works on Windows

Clear definitions of Minecraft modding and launcher terms: `.mrpack`, Fabric vs NeoForge, JVM heap flags, G1GC/ZGC, and Exit Code 1. Understanding how Prism Launcher structures instances, resolves mod dependencies, and launches the JVM on Windows.

Prism Launcher is a fast, lightweight C++/Qt launcher that keeps every Minecraft profile in its own isolated instance folder, with zero ads and no background bloatware.

Get the Windows installer or portable ZIP from /download, or dive into the guides linked below.

Key advantages for modded Minecraft

• **One-Click Mod Loaders:** Switch between Fabric, NeoForge, Forge, and Quilt inside any instance's Version tab.
• **Built-in Mod & Modpack Browser:** Search and update Modrinth and CurseForge modpacks, shaders, and resource packs directly inside the app.
• **Automatic Java Management:** Pair Java 21, Java 17, and Java 8 per instance so modern 1.21 packs and classic 1.12.2 packs both launch cleanly.

Pages in Prism Launcher Technical Glossary

• Instance (Isolated Minecraft Environment) — A self-contained folder holding its own Minecraft version, mod loader, `mods/`, `config/`, `saves/`, and Java settings.
• .mrpack (Modrinth Modpack Archive) — Open modpack package format containing a `modrinth.index.json` manifest and `overrides/` config folder.
• CurseForge Third-Party Download Restriction — Some CurseForge authors opt out of direct third-party API downloads, prompting Prism Launcher to open the exact download link in your browser.
• Minecraft Exit Code 1 & Exit Code -1 — Generic JVM termination codes indicating a Java version mismatch, missing mod dependency, or broken mixin.
• Fabric Loader vs Fabric API — Fabric Loader is the base runtime installed in the Version tab; Fabric API is the standard library JAR placed in the Mods tab.
• JVM Heap Memory (-Xms and -Xmx) — The minimum (`-Xms`) and maximum (`-Xmx`) system RAM in MiB that Java is allowed to allocate for Minecraft.
• Offline Account Profile — Local player profile in Prism Launcher for playing single-player worlds or LAN test servers without an active internet connection.
• mclo.gs One-Click Log Upload — Privacy-safe crash log sharing built into Prism Launcher that strips your Windows username and session tokens automatically.
• Pre-Launch, Wrapper & Post-Exit Commands — Custom shell scripts or executables that Prism Launcher runs before starting Minecraft and after the game closes.
• Sodium & Iris Shaders — The modern open-source rendering engine and shader loader for Fabric and NeoForge that replaces legacy OptiFine.