Several Zkevm have been launched one after another, the OPR ecosystem has become formal, several well-known L2 and two ZKR have not been launched yet. The Shanghai upgrade will be completed soon, and the Cancun upgrade will be next. 4844 will be launched, which is good for L2. I studied various projects of L2 and wrote a brief comparison for everyone to study together. Corrections welcome. #Arb #OP #zkSyncEra #PolygonzkEVM #Starknet