Academy generation reborn is an unofficial derivative of AcademyCraft by Lambda Innovation. Copyright (c) Lambda Innovation, 2013–2016. Original source: https://github.com/LambdaInnovation/AcademyCraft

Original licensing notice, preserved from AcademyCraft:

All versions of AcademyCraft are licensed under GPLv3 (http://www.gnu.org/licenses/gpl.html).
And all versions of AcademyCraft are additionally licensed as following:
Prohibits any person, company, business, organization, etc. from selling AcademyCraft and its contents in any form, including but not limited to paid downloads (including but not limited to various legal currencies, virtual currency, game token, etc.) AcademyCraft's items, the sale of AcademyCraft ability within the game, etc.
Lambda Innovation retains the copyright, the right of authorship, the ownership, etc. of AcademyCraft, regardless of all agreements, and any provision that requires these rights or a part of them is deemed invalid.
Lambda Innovation reserves the right of final interpretation and reserves the right to deny all agreements to revoke all authorizations.

The full GPLv3 text is available at https://www.gnu.org/licenses/gpl-3.0.html. The original bilingual notice is preserved in the JAR under META-INF/ACADEMY-NOTICE. Other bundled components retain their own licenses and attribution.