The engine as a WebAssembly module for your own page or script, with the source version it was built from and how to call it.
Convert a structure to its InChI and InChIKey and back, convert a whole CSV, XLSX or SDF file, learn how the identifier is derived, and practise writing its layers. The InChI engine is WebAssembly running in your browser, so the tool needs JavaScript — and nothing you open ever leaves your machine.