On January 8th, the Arbitrum community voted and implemented the "ArbOS 11 version" AIP proposal. This proposal introduces multiple improvements to Arbitrum, including support for EVM Shanghai upgrade and PUSH0 opcode, as well as various bug fixes. These improvements have now been reviewed and are available for adoption by Arbitrum Orbit, Arbitrum One, and Arbitrum Nova, with the proposal involving the latter two. The proposal states that the ArbOS upgrade can be considered a hard fork of Arbitrum.