GregTech for Minecraft 1.5.1 and 1.5.2. Required Versions listed in each Release.
The Source Code in this Repository is from Version 303d.
More Details on the Release Page
https://github.com/GregTech6/GregTech3/releases/tag/v5.1.31100
https://github.com/GregTech6/GregTech3/releases/tag/v5.2.31100