Several subsequent versions have been released since then, including the development of three Ethereum languages programming specially created to write smart contracts: the Serpent, the Mutan and LLL. To fund the development work, Ethereum has launched an Ether pre-sale public offering. The public offering lasted 42 days and totaled 31 591 Bitcoins, equal to approximately 18.4 million US dollars, or 60 102 216 ETH.
Proof of Concept number 5 was distributed on GitHub on July 22, 2014, simultaneously with the launch of the Ether pre-sale, and included numerous changes compared to the previous Proof of Concept. For the first time, the two clients, one written in C++ and the other in Go, have begun to interact perfectly and work on the same Blockchain.
In August 2014, a client written in Python was added to the list of available platforms.
Crypto for newbies: Ethereum, overview, history and characteristics
With Proof of Concept number 7 Solidity was launched, a hybrid programming language, inspired by JavaScript/C++, containing numerous syntactic enhancements in order to be compatible and versatile for compiling smart contracts on Ethereum.
Block times have been reduced from 60 seconds to 12 seconds using a new GHOST-based protocol. In 2015, Ethereum began using pre-sale fundraising to expand its operations, starting with a foundation based in Zug, Switzerland and with development teams in London, Berlin and Amsterdam.
The beta version with a functioning network and in which mining rewards real Ether, called Frontier, was released on July 30, 2015. In addition, a bug research program was launched open to the developer community. Ethereum is an open source project, and any developer can contribute the source code.
The unit of account of the Ethereum currency is called Ether and is abbreviated from the symbol ETH. Ether is divided into sub-units of account called finney, szabo, shannon, babbage, lovelace, and wei, in honor of Hal Finney, Nick Szabo, Claude Shannon, Charles Babbage, Ada Lovelace, and Wei Dai, respectively, more and less known personalities in the world of cryptography, programming and cryptocurrencies.
The original alpha version of the Ethereum blockchain was called Frontier. The developers did not guarantee its safety.[17] The first modernization of the Ethereum blockchain took place on May 14, 2016 at the 1,150,000 block height.
The new version of the protocol was called Homestead. The update eliminated the Canary contracts from the network. It was stated that network protection based on mining was planned only in the initial phase with the subsequent transition to proof-of-stake only with the hybrid model in the intermediate phase.
Meanwhile, high standards for video memory were employed as a safeguard against the use of specialized mining processors as of July 2017, 2.04 Gb was required. Update Metropolis: Byzantium became the beginning of the transition to the Proof of Stake method.