The Wasm GC and exceptions proposals are both enabled by default in today’s Wasmtime 47 release ! We are excited to help bring more languages to WebAssembly and everywhere that Wasmtime runs. Getting to this point involved large Wasmtime changes and represents the culmination of years of engineering effort. Wasmtime is a WebAssembly runtime that is fast , safe , and portable . It is standalone, lightweight, and easy to embed . Wasmtime maintainers are committed to open standards and actively participate in Wasm standardization. Wasm GC Originally, in the first versions of WebAssembly, high-level languages with an objects-and-references data model, as opposed to a raw-pointers-and-memory data model, had to embed their own garbage collector inside their .wasm binaries. This led to bloated .wasm binaries and many techniques often used when implementing collectors in native code, such as using stack maps and stack walking to identify GC roots, were unavailable.…