If you're looking for mostly 1-to-1 bindings to V8:
https://github.com/denoland/rusty_v8 - maintained by the Deno people
(me and others) and in active use.
If you want something with more bells and whistles (HTTP, TLS, timers,
file I/O, etc.):
https://github.com/denoland/deno (split up in several
crates that you can embed in your own application)