To make it simpler to set up a dev environment for open source mods, so you can help out when you notice something wrong without spending half of your energy setting up a dev environment and all your settings just right. You download this, run the run_me_first.bat, then the gui.bat, and bam, a list of mods that are actually open source. You press the mod you want, you hit the red button, it clones the repo, sets up gradle, and compiles it.
<my lifes story>
Oh! Well, I was making a modpack, and after going through every single mod from another major modpack, finding the license requirements for each and every single one and going ever so slightly insane...
I wanted to see how many mods I could actually compile. I run my own game servers, and every once in a while a mod absolutely shits itself, and throws an exception when the server starts. I wanted to make a tool that would let me, since I am a person with.. not a lot of energy.. with the click of a button set up a dev environment for that mod so I can help out fixing the bug instead of just setting those 'delete all entities that cause exceptions' settings.
I then figured it might be usefull for someone else. So I tried to make it into a simple command line dealio. Type in 'builder name_of_mod', and it downloads the sources, sets up gradle, and compiles it for you.
Then I figured that I wanted to fuck around with making a GUI, and, *patting own shoulder*, it turned out decent-ish.
</my life story>