JR 2025-11-21 -Lightweight JAR Launcher for Windows

Download:

• jr-standalone.exe (193 KB) - Recommended, no dependencies
• jr.exe (23 KB) - Requires VC++ Redistributable

Features:

• Execute JARs like native .exe files (setup file association + PATHEXT)
• Automatic console/GUI detection
• JDK 25 AOT cache support (90% faster startup: 20-30ms vs 200-300ms)
• Works without config OR with simple .jrc config files
• Tiny: 23 KB vs 500 KB (Launch4j) or 50+ MB (jpackage)

Setup:

# Associate .jar files with jr.exe
ftype jarfile="C:\path\to\jr.exe" "%1" %*
assoc .jar=jarfile

# Add to PATHEXT (optional, enables running JARs by name)
setx PATHEXT "%PATHEXT%;.JAR"

Usage:
# Traditional mode (no config)
jr.exe myapp.jar

# Config mode (rename jr.exe to myapp.exe, create myapp.jrc)
myapp.exe

# Run JARs directly (after PATHEXT setup)
myapp.jar
myapp

See README for full documentation.