Welcome to the SurgeOS GitHub organization! Here, you can clone the SurgeOS repositories for building it, help contribute to the OS, or simply just look at the code.
The majority of the project Including the majority of the core of the OS) is licensed under the Apache License, version 2.0. Some parts of it (the kernel sources of devices, as well as kernel prebuilts) are licensed under the GPL.
This is because jpbROM was the past name for SurgeOS (used from jpbROM12 up until jpbROM14.5), and the Telegram group was made before the SurgeOS rebranding was made final.