Astro, built in the browser, on CellB

Each page reads an app's sources, builds them in this tab (esbuild and Astro's compiler as WebAssembly, packages from the npm registry) and runs the result on CellB, served from the tab at this origin's root. One app at a time: building the other replaces it.

• A small Astro app (a few seconds)
• EmDash, the Astro CMS (about two minutes the first time, a few hundred packages)