To download ATLauncher you need to select the correct version. If you are running Windows then you should select the 'Windows (.exe)' button. If you are running a Mac,Linux or prefer to use the jar file, then you should select the 'Linux/Mac/Others (.jar)' button.
A small mod to add CraftTweaker support for Galacticraft. 5,252,393 Downloads Last Updated: Dec 14, 2018 Game Version: 1.12.2. This Modpack has been around sense Galacticraft was in beta on 1.4.2 Mc (Aka late 2012). It was the first mod pack made for Galacticraft. Lapito The guy who made the pack got permission from micdoodle back when he made the pack.
Put the exe/jar file in its own folder somewhere on your computer such as on your desktop or documents folder, making triple sure you place it in it's a new blankfolder.
Galacticraft Core Download
Once downloaded and placed somewhere it's as simple as opening it like you do any other application. Once ATLauncher is open you can then go to the 'Accounts' tab andenter in your Minecraft Username/Email and Password combination to add your account and start playing packs.
Galacticraft Mac Download Version
To play a pack just simply navigate to the 'Packs' tab and click 'New Instance' on any of the packs you want to play. Optionally give it a name and pick a version to installand click Install and the process will run through and by the end you will have a working instance which you can play in the 'Instances' tab.
For a more details walkthrough on how to download and install ATLauncher, please watch the Installation Video below. If you have any issues then please feel free to joinour Discord to get some help.