j5mclaunch was made so I could launch older versions of the game on a Java 5 system (like a PowerPC mac)
Because 4.0 changed to use BouncyCastle instead of cURL, MacPorts is not required to run the game. However, starting the launcher is now way slower (~2 minutes on my 1.33ghz iBook, ~5 seconds on my 2016 desktop) because of it.
- Transfer the JAR onto a USB thumbdrive
- On your PowerPC mac or Windows 2000 desktop open j5mclaunch
- Press login and open the URL in a browser (if it doesnt work in TFF:
https://login.live.com/oauth20_authorize.srf?client_id=00000000402B5328&redirect_uri=https://login.live.com/oauth20_desktop.srf&response_type=code&scope=service::user.auth.xboxlive.com::MBI_SSL) - Paste the URL of the page with the warning page, you'll need to be quick to copy it because the code disappears after ~5 seconds.
- Press "Play" and wait for everything to download
This does NOT install modifications like OptiFine by default. It is only the launcher. You need to go to the versions folder and mod your own jars.
You need to download 1.5.2 and 1.6.4 jars and place them into the libraries folder in the root of the project due to the shim requiring them. The rest of the launcher needs to be built using OpenJDK 8 due to newer versions removing the Java 5 target. Building has only been tested in IntelliJ Idea Community 2024 and 2025.
It "works" I guess, I got 1.2.5 to run a singleplayer world at 2 frames per second (worse performance than with java 5) on my 1.3ghz iBook G4 14"
You can intall it here: https://forums.macrumors.com/threads/how-to-install-java-6-and-7-on-ppc-os-x.2190159/ but I suggest only doing it if you need a modification that *requires* Java 6 (I haven't tested Forge, all I know is that those older versions need help downloading libraries or they crash)
Be aware that on Tiger it doesn't set Java in path successfully, but this launcher will use the symlinks the Java Updater makes so you can use the scripts to change version on MC