... read the wiki for more details on how to submit a pull request (PR). Besu is an Apache 2.0 licensed, MainNet compatible, Ethereum client written in Java. Participation in private networks is typically restricted in some way, so the volume of traffic is much lower than on Mainnet, resulting in lower system requirements. Depending on your environment and network setup, the minimum Java Virtual Machine (JVM) memory requirement for private networks is 4 GB.