Since its inception in 2015, Ethereum has undergone significant updating, with no less than 45 formal changes made to the protocol by December 2022. These changes, known as Ethereum Improvement Proposals (EIPs), have addressed a variety of issues and introduced major features that shape the network today.
Some of the most notable changes include:
The DAO Hack: This event created a contentious hard fork as developers chose to force a revision of the blockchain history on the community, leading to Ethereum splitting into two chains, Ethereum Classic and the current Ethereum network
The Merge: Ethereum transitioned from Proof of Work (PoW) to Proof of Stake (PoS), changing transaction settlement, the roles of network participants, and laying the foundation for future scaling plans.
Gas Cost Adjustments: The gas costs for different opcodes have been changed multiple times to prevent misuse and/or adjust the resource cost of available functions
Base Fee Burning: Instead of sending base transaction fees to network operators, they are now burned, reducing the circulating supply of ETH and introducing a deflationary mechanism
Block Reward and Size Adjustments: Ethereum has adjusted block rewards and block sizes multiple times, adjusting incentives and transaction throughput
Ethereum continues to progress along several different lanes such as protocol scaling, light client improvements, and censorship resistance. These efforts are part of an ongoing development roadmap designed such that Ethereum can continue competing as the leading cryptocurrency platform for a wide range of applications and digital assets.