Ethereum was the first public blockchain to allow the programming of Smart Contracts in the block chain itself. Ethereum was originally proposed in late 2013 - the initial system went live on 30 July 2015.
Prerelease Step 0: Olympic testnet - launched May 2015
Release Step One: Frontier - launched 30 July 2015
Release Step Two: Homestead - launches 14 March 2016 (Pi Day - considered first stable release)
Release Step Three: Metropolis - TBA
Release Step Four: Serenity - TBA
The first important milestone for Enterprises took place in In October 2016, when JP Morgan Chase unveiled Quorum, an effort to extend blockchain technology with Enterprise capabilities.
In February 2017 the formation of the Enterprise Ethereum Alliance (EEA) was announced. The EAA was established to build on Euthereum to define enterprise-grade software capable of handling the most complex, highly demanding applications at the speed of business.https://entethalliance.org/
Ethereum Foundation, Ethereum/Metropolis (vByzantium), all