Polkadot’s Gavin Wood: WebAssembly Is the Future of Smart Contracts, but ‘Legacy’ EVM Is Right Now (2025)

The Ethereum Virtual Machine (EVM) has the pole position among blockchain developers. That's why Gavin Wood says it's important for his Polkadot system of blockchains to support it — at least for the foreseeable future.

Wood was the lead developer when Ethereum was built and is now the founder of Parity Technologies, which created Polkadot and is in the middle of finally rolling out its system of interconnected “parachains.” The EVM is what enables Ethereum to run smart contracts, the innovation it's known for popularizing. When the original team built Ethereum, they tried not to stray too far from what the world was familiar with at that point, which was Bitcoin, Wood said.

Speaking at Consensus 2021, Wood acknowledged the EVM's place in blockchain development today.

"I can't deny that a lot of people are already using EVM, so it's super important to support these legacy protocols, these legacy languages, and that's what we're doing with Polkadot,” Wood said in a pre-recorded interview. “People like EVM, people use EVM – absolutely fine until the next generation really proves its mettle.”

Polkadot aims to prove itself as a leader in that next generation of smart contract blockchains.

The EVM has lots of developers and lots of software tools they can use to make coding easier. Other blockchains are playing catchup with those tools, so, Wood said, "It's foolish to just throw those away. But it's not foolish to start thinking about where the next thing is, and that for me is using WebAssembly as smart contracts."

WebAssembly is a software format that works across the web and works easily with multiple software languages. It was built by the giant web companies and works on all the major browsers.

Polkadot announced May 17 that its sister network, Kusama, had enabled the launch of parachains, the networked chains that allow Polkadot to run different blockchains with different logic but shared security. This is a key final test before running the same upgrade on Polkadot itself. If that happens, it would represent a realization of the Polkadot vision, which has been in the works since a $147 million initial coin offering in October 2017.

While Ethereum's existence enabled Parity to raise funds to launch Polkadot, the project was always meant to go beyond the original smart contract blockchain.

"You see, the problem with EVM is it's a hugely opinionated design. It derives from an already very opinionated design, which is the Bitcoin script design," Wood said. His team wanted to give developers a very non-opinionated format to work with, and that's WebAssembly.

Wood also said he believes it's time for blockchains to move on from the idea that upgrading software is bad or dangerous.

"Blockchains are not fit for purpose in the modern day, like legacy blockchains that rely on hard forks, rely on thwarting their own consensus, are not fit. for modern-day use. It's as simple as that," Wood said. "People expect automatically upgrading apps. They expect automatically securing systems, and they expect it with a minimum of fuss."

Polkadot comes with its own system for making upgrades on-chain, which Wood said is crucial. But he also explained that Polkadot runs on an extremely simple base protocol that will remain unchanged. The changes will occur a layer up from the base, and that should protect Polkadot as a whole from accidental or surprise forks, he said.

"If you do it this way, then you can stay ahead of the curve. You can stay on top of technological development. And it won't be too long before people realize, maybe we should make a blockchain that does that as well," Wood said. “But as far as I know, at the moment, Tezos is the only one that kind of has this kind of functionality."