Execution environment / virtual machine

One of the important primitives in the Based Stack is the separation of sequencing and execution.

Sequencing	Coming to consensus on the inputs to a State Transition Function (STF).
Execution	Coming to consensus on the output of an STF.

At Spire, we group concepts like validity proofs (aka ZK proofs) and fraud proofs, but also virtual machine (VM), which is what we will focus on in this section. We believe that developers should be able to choose the virtual machine that works best for their application.

The Based Stack is designed to eventually support multiple VMs.

We are especially interested in combining the throughput and scalability of alternate virtual machines like the MoveVM and the SVM to scale Ethereum applications with innovative features like localized fee markets, parallelization, and highly optimized node software.

At launch, the Based Stack will include support for the EVM with OP Stack fraud proofs as we believe that the EVM is, in practice, the most useful for many types of applications. EVM support is especially important for applications that have already deployed on Ethereum and therefore, have written their code bases for the EVM.