In theory Wasm could be supported, but generally JS/TS is much more efficient when running inside isolates (our lightweight sandboxes) since you don't have to bundle a language runtime into the app. CFOS at present only exposes JS (with TS coming soon).
I'm making a whole new language to get around the problem you're talking about: it brings no runtime at all. One of my targets is a Sandstorm like system I've been slowly working on, but I'd love for it to be a fit for the actual Sandstorm successor.
> workerd tries to isolate each Worker so that it can only access the resources it is configured to access. However, workerd on its own does not contain suitable defense-in-depth against the possibility of implementation bugs. When using workerd to run possibly-malicious code, you must run it inside an appropriate secure sandbox, such as a virtual machine. The Cloudflare Workers hosting service in particular uses many additional layers of defense-in-depth.
Sandstorm was great because it did proper sandboxing. This is pretty weak by comparison.
Workers are in the same process but have separate heap, global vars, gc etc, the isolation is managed and achieved by V8. It is much lightweight compared to micro VM or containers. But the downside is you have to use JS because of V8.
