Ethereum-flavored Web Assembly (eWASM)

• From a post about the Serenity roadmap:

"In Phase 2, the functionality of Ethereum 2.0 comes together. With the introduction of a new Virtual Machine — Ethereum-flavored Web Assembly (eWASM) — shard chains evolve from fairly rudimentary data markers to fully-functional transactional chains, capable of scaling the Ethereum network.

In order for a blockchain ecosystem to operate, nodes must execute transactions and smart contracts in a virtual machine. Ethereum 1.0’s virtual machine was called the Ethereum Virtual Machine (EVM). With the switch to Ethereum 2.0 and the Beacon Chain, the network’s virtual machine will be upgraded to eWASM, a virtual machine based off Web Assembly, which is defined by the World Wide Web Consortium (W3C) as an open-source standard. Because WASM supports a number of coding languages, eWASM could allow smart contracts written in any language to be executed on Ethereum, as opposed to just ones written in Solidity in today’s EVM."

• From this blog (31-8-2019):

"Ewasm will replace the EVM as the state execution engine of the Ethereum network and is expected to be one of the final aspects of Eth 2.0 to be integrated. Ewasm (Ethereum WebAssembly), is a “restricted subset of Wasm” that has been modified specifically for the Ethereum network. One of the major targets is to provide an EVM transcompiler and a metering injector, preferably as an Ewasm contract.⁶ Another is a clear specification of the Ethereum interface and Ewasm contract semantics.⁶ Finally, the team aims to implement an Ewasm backend for the Solidity compiler and to provide instructions and a library for writing contracts in C and Rust.⁶ The differences between Ewasm and wasm can be thought of in the following way: Ewasm = Wasm — nondeterminism (floating point) + metering + EEI methods (used to interact with Ethereum). Ethereum will join projects like Polkadot, Cardano, EOS, Tron, Spacemesh and NEAR protocol, who have either already adopted or are in the process of adopting Wasm.⁹"