The massive size of browser engines has concentrated power over the web platform into a few large corporations. Creating a new browser engine that is sufficiently featureful to be an alternative to the Big Three is practically impossible. But what if we could shrink the footprint of a browser's core? What if a browser was little more than a WebAssembly (Wasm) runtime and nearly everything else was an extension? By breaking up the monolith we would have a chance to re-decentralize control over the web. This talk will explore what a modular web platform might look like with Wasm at its core, with a focus on how Wasm GC enables the mission-critical feature of safely sharing resources amongst components.