.jar pack
Creating the .jar.pack
Take the desired .jar file and run it through the pack200 tool that comes with the JDK.
How to use Pack200 on Windows
Copy pack200.exe and jli.dll from the JDK folder, to the folder with the .jar file in. Use CD to get to the folder using the Command Prompt. Run the following code, and you should have a .pack file
pack200 --no-gzip launcher.jar.pack launcher-X.Y.Z-all.jar
(That command makes launcher.jar.pack from launcher-X.Y.Z-all.jar in the same folder.)