This mandatory release improves the long term stability, sustainability, decentralization, and performance of the blockchain by removing the ASIC-resistant PoW (which requires frequent forking in an arms race with ASIC-developers) and replacing it with the much faster-to-verify and ASIC-friendly (currently FPGA-friendly) Keccak-based KangarooTwelve (K12) algorithm. The use of K12 for PoW was reviewed and approved by the Keccak-team, developers of Keccak/SHA3.

It also contains numerous other improvements for reduced transaction size, improved fungibility, safer long-term blocksize growth, and dozens of performance and reliability patches.

The mainnet fork date is scheduled on October 25 (height 1146200)

Changes include:

KangarooTwelve (K12) Keccak variant PoW for FPGA- and eventually ASIC-friendly protocol stability
Borromean signatures for smaller transactions
Tighter big bang protection preventing exponential blockchain growth
Consensus lock time aligned with reference wallet preventing alternate wallets from damaging fungibility
Fixed ring size at 3 for improved fungibility
Gamma-distribution selection on non-RCT outputs for better ring member ambiguity
Improved non-RCT tx output selection for reduced transaction linkages
Upstream reliability and performance improvements
AEON community-contributed improvements

Thanks to stoffu for the majority of the AEON-specific work and additional thanks to all of the AEON community and upstream contributors