webcontainer-core

er, which is also excellent but isn't the right fit for a code sandbox like jsbin/CodePen/CodeSandbox/etc, which needs to be able to run whatever can be run in a browser tab. What WebContainers does is use some hacks to sort of run node apps in the browser, so instead of using something like the browser version of rollup, you can use something like vite. You can also see the console output that vite would provide. When vite installs esbuild I think it probably specifies the non-WASM esbuild. So it's likely running patched vite and running WASM esbuild. It uses a fake npm and yarn and shows npm and yarn in the output. This explained in this FAQ under "Do you support yarn or only npm?": https://github.com/stackblitz/webcontainer-core#faqs It has an iframe sandbox with same-origin which means in order for it to be contained, you need a subdomain. This is something other major sandboxes do like jsbin and CodeSandbox. This is why IMO it doesn't provide container tech. That's lucky, because custom container tech on the web winds up being like Google Caja which was a marvelous accomplishment but not nearly as robust as Docker, MicroVMs, WASM, or the browser security model (<iframe sandbox>, CSPs, and more): https://en.wikipedia.org/wiki/Caja_project https://devd.me/papers/LeastPrivileges.pdf