FunctionalScript runs two ways: as the JavaScript it already is, and compiled by fjs compile to Rust on the NaNVM runtime, then to WebAssembly. These pages run the same source both ways, side by side, and show every step in between: the source, the Rust, and the WebAssembly text (WAT) of the functions compiled from it. The design is in todo/wasm-demos.md.

Each of these pages runs a whole program, which writes to standard output, and compares what each run wrote and how long it took.

• Hello, world: the smallest program, a greeting written byte by byte.
• Sorting: a quicksort of 100,000 integers, which allocates as it goes.
• Collatz: the longest Collatz chain below 30,000, arithmetic with no allocation.

Every feature page of the language specification whose status is "implemented" runs its own example the same way: the page shows the expression graph (EDAG) the example lowers to, the Rust, the WAT, and a Run button that calls the example with the inputs its page lists, as JavaScript and as WebAssembly. The comma operator was the first. The constructs FunctionalScript refuses have pages of their own, listed in each area of the specification, and the ones not yet decided are on the Undecided page.

• samples lists every sample, with the calls a feature page makes and the answers JavaScript gives.
• npm run gen compiles each sample to nanvm/demos/gen.samples/<name>.rs, committed, with a Rust test per listed call, so the two runs a page compares are tested before it is deployed.
• nanvm/demos/gen.build.sh, which npm run gen writes, builds the nanvm-demos crate for wasm32 into nanvm/demos/wasm/ and prints each sample's WAT beside it. Both are ignored build artifacts. Cloudflare builds them before generating the website. For a local website build, first run ./dev.sh sh ./nanvm/demos/gen.build.sh, then npm run website.