Offline Go workstation, running entirely in this tab from the seeded standard library — no server. Try the “What the Go Playground can't do” gallery (top right): each button launches a small Go program in the desk below that breaks a Playground limitation — a real filesystem, a network (a Go server and a Go client over an in-tab virtual loopback), processes and pipes, a real wall clock, an animated GUI, and the Go toolchain itself compiling here. Everything here works client-side; browsing the live web and external deps need go run ./serve — see the repo.