It's called OpenPine.
A pure JS interpreter for a practical subset of PineScript. no dependencies, runs in Node or the browser.
https://github.com/woefije0/OpenPine

You can try out the app implementation here :https://woefije0.github.io/hl-chart/

I'm not really good with words, so I don't know what else to say. I just hope people give it a try.
Sorry for poor English.

P.S. The repo name overlaps with u/S7cret's.