Plasma EVM provides a EVM-compatitable plasma chain with scalability and security. Plasma is scalability solution for Ethereum, making layered blockchains that data in child chain is summarized and committed to root chain.
Plasma EVM can reuse any solutions and framworks on Ethereum like Soldiity, Truffle, Metamask, and even MyEtherWallet.
The major differences from other plasma proposals are as follows:
Supports EVM computation
Supports global state for a single transaction
You can follow how this design came out from scratch here.