Spynach, EPReasy and ctps running in Pyodide. Pick an NMR, EPR or pathway example, edit it, run it. Every calculation goes to a web worker, so the page stays responsive.
Ctrl+Enter runs. show_spectrum, show_fid and show_image draw on the right; an epreasy spectrum can be passed as is, and EPR axes run left to right. The 12800-orientation powder is the slow one, about a minute; the 1600-point powder, magic-angle spinning and the fit take a few seconds. Grid names such as leb_2ang_rank_17 are loaded from src/spynach/grids. A link such as try.html#ex-epr-hyscore opens and runs one example.
The spectrum will land here.